i'm obivously very stupid, because i cann't find out if/how i can put my old recordings [live mono theatre events & unclassic vinal] onto/into an MP3 juke box. Is there a box on the market that one can just put analog into? [& what peciluar lead is required?]

I don't think there's anything quite that simple, but you can plug your stereo into a sound card, record the information to disk and then convert it to MP3. Have a look in the 'Other' Hardware section on this site for a review of the Terratec Phono PreAmp Studio which should do the trick.
Alex

The TerraTec Phono PreAmp does work great -- if you have the configuration to get it set up properly. One bizarre thing about the design is that the amp doesn't have it's own power supply -- you have to plug it into the "game port" of a consumer-grade sound card, such as a Creative Labs SoundBlaser. Since all I had was a pitiful MAudio AP2496, I had to buy a SECOND sound card just to provide power to the preamp. An extra $80 in my case. Quite a pain.
That being said, once set up, it sounds great. Using a pro-quality needle (Stanton Groovemaster or something similar), you will have minimal noise and your "curve" will be taken care of. But you will need to clean up the sound a little bit -- I suggest something like SonicWorx Power Bundle, or one of their other products. Usually a de-click/de-crackle and some EQ will bring the sound up to speed with a CD.
As far as the MP3 conversion goes, just use whatever you normally use once you get the .WAV or .AIFF. Warning -- to do it right, you do have to spend some time. Processing and converting the sound files, even on a fast system, takes a while. It normally takes me 40 minutes to record and process a 6-minute song from vinyl (on a Power Mac G4 500MHz).
Good luck!