I'd go with a money market as opposed to a CD. It's the same as a CD, but you can withdraw it anytime you want (might be less interest rate though).
For me, I've put some money on diversified stocks and mutual funds as well as money market accounts. The past 6 months though, I've put my money on MM account online. I came across this site called <emigrantdirect.com> and it's better than any banks CD or MM accounts I've put my money in. They give 5.05% interest and you can transfer it back and forth to your checking account whenever you want to. It only takes about 4-5 days (at most) in between. Oh yeah, btw, this site is legit. Financial gurus and books refer to it at times.
Also, you can put money on Paypal as well. I don't know how much they give now but it's much better than having your money sit in the checking or savings for less than 1% interest, IMO. HTH a bit!