I have an old Tascam Portastudio 564(I think it's a 564). It's actually a minidisc recorder that can double as a nice digital mixer. The later and refurbished models can take a regular 74 minute disc and record and entire show (or in my case, a set - I can sing for a LONG time). The resulting quality is not CD worthy, but it is mp3 quality. Nice to have.

I have not had the same luck working with a hard drive Portastudio in live situations.

You can get them on Ebay for around $150-$175.

Dan