QUOTE(bean52 @ Feb 16 2010, 05:00 PM)

I do most of my practise on a Yamaha P150 electric piano. It would help a lot if I could record myself practising and play it back but the P150 doesn't have any built in means of doing so. It does have MIDI in and out sockets so I know it could be connected to a computer, but as the piano is upstairs at the front of the house and the PC is downstairs at the back this isn't really a practical option! I don't need a fancy box of tricks, just something that will record and playback. Money's a bit tight too so I'd probably be looking for second hand. Can anyone advise me what I should be looking for? thanks
MIDI doesn't send audio information, so that's not really much of an option unless you have a good virtual piano VST or something on your PC to record with.
According to Yamaha's website, your piano has:
LINE OUT (L/MONO, R; unbalanced, 1/4" phone); PHONES
Sockets, so you can record from the Line out with a cable like this..

2x1/4" phone (TRS) to 3.5mm jack. You can put that into the line in of a laptop/PC or something and record via Audacity.
Otherwise... one of these to connect to a hi-fi or cd-recorder (although some might have a 3.5mm jack).

2x1/4" phone (TRS) to 2 x RCA
HTH