I just finished a review of the Black Box, an interesting piece of gear that combines beat-synched guitar effects with a drum machine and USB audio interface. It's got a mic input, too.
It's mostly for electric guitars, but it can add some color to your acoustic guitar playing (there's one audio example with my Taylor 414K.) And it works with virtually no processor load on you computer, so it'll let you record guitar and vocals with an underpowered laptop.
I think it's pretty cool. No, I have no financial ties to M-Audio, tho' I do get paid by O`Reilly for reviewing stuff.
My only concern with anything from M-Audio is that their stuff is great as long as it works but if it breaks their customer support is about as bad as it gets. (In other words, buy the extended warranty!)
Craig My goal is to be able to play as well as people think I can.