ive seen some computer jukes that run on Linux operating systems and was wondering if the raspberry pi has the operating capabilities to run one, since it only has a puny 256 megabytes of RAM
Which is essentially a backend to control playback and management of music etc. You can have a frontend on your droid and then control the machine remote through that.
If you are not looking to run this on the PI - I suggest taking a look at http://linux.voyage.hk/voyage-mpd which is a standalone linux distribution built with a lil interface, MPD, and the remote control drivers all as one package which can be booted and ran from a USB / SD / CF.
Another option (it will run slower than poop) would be to try and get a MythTV port running on ARM .... but you would have better luck with XBMC if you just want a frontend to play music.
Both are not a "jukebox" in the traditional sense though. I would imaging you would want something that can associate "F12" for a specific song, etc.
There is a JPIO header which you could in theory map to some kind of keyboard shortcut etc... it would be up to the software to recognize what a "credit"..
The coinmech would simply short out two pins.
Personally, I would just go with freeplay.
If it were me, I would get a touchscreen and use XMBC or something like that as a frontend. Get a small mini keyboard and mouse if you can't get a touchscreen.