We're in the same boat as you are. We have four children in a 3 bedroom, 2 bath, less than 1500 square foot home and a fifth in college who comes home for visits. We too bought in 2005, while still owning a home in another state, which is why we went small. We planned to sell after getting rid of the first home, then the market crashed. I often joke, saying if we live here too much longer, Mom's gonna be on meds, but truly, love does grow big in small spaces. I agree with the post which reminds us that while our generation wants big and we want it now, previous generations lived in quite small homes, with 2, 3 and 4 children. We have 3 boys who share one room and a daughter who has her own room, but wishes she could bunk up with the boys...the one person in the house who has her own space and she doesn't want it. LOL While our older two boys say from time to time they want their own rooms, I honestly believe if and when that happens, they will miss the fun times and closeness they have together sharing a room. Yes, we could have more space and be a bit more comfortable, but I also think it's kind of fun to find ways to maximize the space we have, upgrade here and there and most importantly, teach our children to value and care for what we have be blessed with.
On another note, I would NOT recommend a short sale, as was recommended in a previous post. This not only damages your credit, but if you go right into purchasing another home, that's another red flag to lenders. They're taking a risk by lending to someone who might possibly jet and/or sell their Mortgage lower than the original Note. For us personally, we are taking this opportunity to focus on getting in the best financial place we can. If you're not familiar already, check out daveramsey.com. Pay off your debt, including your home if possible and as Dave says, live like no one else today, so you can LIVE live like no one else tomorrow then REALLY get what you want when the market is back up and you have plenty in the bank.
Just a little food for thought. :-) Wishing you the best in whatever you decide...