If you've got a top-end computer, AVID used to offer a free download that you may still be able to track down. Mind you, as it's used professionally it may be a bit of overkill!
I've never used these, but here's a couple of others:
http://www.jahshaka.org/
http://www.zs4.net/
Also, most CD burning software comes with some sort of editing package. Must say that (apart from it's tendency to lock out and it's non-user friendly export options) I find WMM quite a nice little programme.