hey i've been experimenting with recording my jams with my band... best results i got was when we jammed in fourtones big studio, i think its best if you guys wanna record a good demo of your songs..
other than that, i use the itunes memo recorder. very decent for something so cheap (if you have an ipod that is).. i suggest just tape a little cotton around the mic itself to further reduce unwanted sounds, and your jam should be recorded well. and yeah, don't put too near amps and the drumkit.
good luck