Zoom R8 Multitrack Recorder.
I used this to record rehearsals with a feed from the desk and a room mic. Records for hours. I just started it recording and left it on for the whole jam. Got a whole bunch of sequencer features etc I never used. Runs off AA batteries or usb battery pack. Blurb from website: R8 Features 8-track playback, 2-track simultaneous recording Built-in stereo condenser microphones Records directly to SD and SDHC cards up to 32 GB Records 16-bit/24-bit, 44.1 kHz/48 kHz mono and stereo WAV files Dual