Toddlers and social interaction

As a followup to some of last month's posts about staying at home (I didn't blog as much as I would of liked to about alot of the research and conversations my wife and I had), we decided that instead of one of us stopping work all together, we would adjust our schedules. I have now been going into work earlier and have worked out with my company to leave in the middle of the day and then come back and work later into the night. Our main reasons for this are two-fold:

1. Money
2. Time with our children

But I keep coming back to a third issue as well...

3. Child's social interaction

While I would like my wife and I to be the two people who raise our sons, I also want them to be able to play with kids their age. Daycare provides a nice venue for that, but there must be some other ones out there. We are fortunate enough to have children early in our lives together (we are both in our mid 20s), but one of the downsides is that none of our friends have children yet. The playground is a nice place to interact with others in the summer. In the Minnesota winter though, it gets a bit sparse :) I'd like to hear some ideas from anyone else who doesn't send their child/children to daycare, but has found a good outlet to allow them to develop those social skills with peers.