Activities for babies?

[JeepFreak]

Besides being an independent real estate broker, I'm also a stay-at-home father of a 7 month old baby girl. It's getting a bit harder to keep her entertained, so I've been looking for suggestions!

The cheaper it is, the better! Last week we walked the bike trail by the river and that was nice. Free admission day at the zoo (and several museums) is coming up on 2/5.

Do you guys have any other suggestions?

Thanks!
Billy