In no particular order, here's our current (but continually growing!) list of activities:

1. ride bikes
2. roller blade
3. basketball
4. play board games
5. make a tent out of blankets
6. squirt with hoses
7. run through the sprinkler
8. jump rope
9. read books
10. blow bubbles
11. make homemade play dough
12. play with play dough
13. press flowers
14. do crafts with pressed flowers
15. write a letter to a relative, friend or pen pal
16. clean bedroom
17. vacuum living room
18. clean bathroom
19. make a craft
20. draw
21. color
22. paint
23. pull weeds
24. watch a movie
25. write stories
26. use binoculars
27. use magnifying glass
28. use microscope
29. bird watching
30. write a play
31. act out a play
32. invent circus acts
33. perform a circus
34. play card games
35. make art on the front walkway with sidewalk chalk
36. play catch
37. play baseball
38. collect rocks
39. collect leaves
40. collect feathers
41. play Frisbee
42. make Frisbee's out of old plastic lids, decorate with markers
43. dust the house
44. brush the pet
45. write letters
46. read a magazine
47. play dress-up
48. play Cowboys
49. pick vegetables
50. play outside with the pet
51. build a fort in your rooms
52. build a fort in the backyard
53. do a jigsaw puzzle
54. play the Geo-safari
55. play on the computer
56. listen to a story or book on tape
57. do extra schoolwork to get ahead
58. do brain teasers (crosswords, word searches, hidden pictures, mazes, etc.)
59. cook
60. prepare lunch
61. surprise a neighbor with a good deed
62. play store
63. prepare a "restaurant" lunch with menus
64. hold a tea party
65. have a Teddy bear picnic
66. play with toy cars
67. play dolls
68. play house
69. chase butterflies
70. collect caterpillars and bugs
71. plant a garden or a pot
72. collect seeds
73. hunt for four-leaf clovers
74. learn magic tricks
75. put on a magic show
76. plant a container garden
77. sprout seeds or beans
78. make sock puppets
79. put on a puppet show
80. make Christmas presents
81. make homemade wrapping paper
82. make homemade gift cards
83. make picture frames from twigs glued onto sturdy cardboard
84. crochet or knit
85. make doll clothes
86. sew buttons in designs on old shirts
87. run relay races
88. make bookmarks
89. take a quiet rest time
90. take a shower or bath
91. bathe a pet
92. feed the birds or squirrels
93. watch the clouds
94. organize a dresser drawer
95. clean under the bed
96. empty dishwasher
97. vacuum under the couch cushions and keep any change found
98. write these ideas on pieces of paper and pick out one or two to do
99. whittle
100. whittle bars of soap
101. practice musical instruments
102. perform a family concert
103. teach yourself to play musical instrument (recorder, harmonica, guitar)
104. fold laundry
105. sweep kitchen or bathroom floors
106. sweep front walkway
107. sweep or spray back patio
108. sweep or spray driveway
109. wash car
110. vacuum car
111. vacuum or dust window blinds
112. clean bathroom mirrors
113. clean sliding glass doors
114. clean inside of car windows
115. wash bicycles
116. clean garage
117. play in the sandbox
118. build a sandcastle
119. work with clay
120. copy your favorite book illustration
121. design your own game
122. build with blocks or Legos
123. create a design box (copper wire, string, odds-and-ends of things destined for the garbage, pom-poms, thread, yarn, etc.)
124. plan a neighborhood or family Olympics
125. have a marble tournament
126. paint a picture with lemon juice on white paper and hang it in a sunny window and see what happens in a few days
127. finger paint with pudding
128. make dessert
129. make dinner
130. give your pet a party
131. paint the sidewalk with water
132. start a journal of summer fun
133. start a nature diary
134. have a read-a-thon with a friend or sibling
135. have a neighborhood bike wash
136. play flashlight tag
137. play Kick the Can
138. check out a science book and try some experiments
139. make up a story
140. arrange photo albums
141. find bugs and start a collection
142. do some stargazing
143. decorate bikes or wagons and have a neighborhood parade
144. catch butterflies and then let them go
145. play hide-and-seek
146. create a symphony with bottles and pans and rubber bands
147. listen to the birds sing
148. try to imitate birdcalls
149. read a story to a younger child
150. find shapes in the clouds
151. string dry noodles or O-shaped cereals into a necklace
152. glue noodles into a design on paper
153. play hopscotch
154. play jacks
155. make up a song
156. make a teepee out of blankets
157. write in your journal
158. find an ant colony and spill some food and watch what happens
159. play charades
160. make up a story by drawing pictures
161. draw a cartoon strip
162. make a map of your bedroom, house or neighborhood
163. call a friend
164. cut pictures from old magazines and write a story
165. make a collage using pictures cut from old magazines
166. do a secret service for a neighbor
167. plan a treasure hunt
168. make a treasure map
169. make up a "Bored List" of things to do
170. plan a special activity for your family
171. search your house for items made in other countries and then learn about those countries from the encyclopedia or online
172. plan an imaginary trip to the moon
173. plan an imaginary trip around the world, where would you want to go
174. write a science-fiction story
175. find a new pen pal
176. make up a play using old clothes as costumes
177. make up a game for practicing math facts
178. have a Spelling Bee
179. make up a game for practicing spelling
180. surprise an elderly neighbor or relative by weeding his/her garden
181. finger paint with shaving cream
182. collect sticks and mud and build a bird's nest
183. write newspaper articles for a pretend newspaper
184. put together a family newsletter
185. write reviews of movies or plays or TV shows or concerts you see during the summer
186. bake a cake
187. bake a batch of cookies
188. decorate a shoe box to hold your summer treasures
189. make a hideout or clubhouse
190. make paper airplanes
191. have paper airplane races
192. learn origami
193. make an obstacle course in your backyard
194. make friendship bracelets for your friends
195. make a wind chime out of things headed for the garbage
196. paint your face
197. braid hair
198. play tag
199. make a sundial
200. make food sculptures (from pretzels, gumdrops, string licorice, raisins, cream cheese, peanuts, peanut butter, etc.) and then eat it
201. make a terrarium
202. start a club
203. take a nap outside on your lawn
204. produce a talent show
205. memorize a poem
206. recite a memorized poem for your family