If you're gonna go with a savings account, definitely go with one of those online savings ones, like the other poster mentioned. I just recently opened one with HSBC (hsbcdirect.com) since they always seem to have the highest interest rate (currently at 5.05% I believe).
A good tool to use is a savigs calculator (such as this one:
http://cgi.money.cnn.com/tools/savin...vingscalc.html ). According to this one, if you start with $3500 and save $100 a month for 20 years, you'll have $50k in 20 years, not adjusted for inflation. These things are kinda fun to play around with in general.
In this case, I put in 5% as the average rate of return per year but you can also put your money into some sort of an aggressive market growth fund and maybe assume 8-9% growth per year on average, and plug that into the calculator and see what happens.