We just recently went on a trip from NC to Seattle, DS's first plane trip. We did all kinds of stuff like sailing and exploring the city. We got so spoiled by how well DS was sleeping because he was getting so much activity each day.
Now we're home and he's not sleeping as well. Who knows of any good activities for young babies? We already take a baby swim class but it's only once a week. We can always go for a stroll in the park, but that's not much exercise for him. Other than lots of tummy time, I can't think of anything.

Re: Activities for Babies
Our "leave the house" schedule:
Monday-Grocery Shopping
Tuesday-DD goes to Gram's or tags along for errands
Wednesday-Story Time at Barnes & Noble
Thursday-DD goes to Gram's or we schedule a play date
Friday- Park or Indoor Playground