Having not tried a Yamaha board for some time now, I can not give my recommendation, but this implementation looks cool.
Its a USB multi-channel mixer that comes with recording software. There are two versions available; the MSW10, and the MSW12, which have 10 and 12 channels respectively.
The included software is Cubase LE by Steinberg (which I have also not used), and will work with either Mac OSX, or Windows 2000/XP/XP Pro. The system requirements are fairly liberal, so most should not have a problem. Here is the product page.
If you have experience with this sort of thing let me know, I am considering something like this for my setup.