Great thread! Love some of the ideas.

Some of the things we do with our 19 month old:

Classical radio - DS loves it! and no ads.
Make a cubby with some big cardboard boxes - make sure you cut a hole in for a door as that is the best part)
Go for a ride on the bike (we just bought a weeride!)
Midday bath with bath toys (it gets hot here)
Local water park (so cheap - only $2.50 to get in with a toddler)
Playgroup/park
Sandpit
Walk the dog
Books
Pretend play with soft toys

Really want to get into some more crafty things so this thread has inspired me to do a bit more like that. Thanks guys!