are there any apps that can compress an mp3 file so that I can fit more into my mmc?
or any app that downsize/lower the quality of the mp3 to make it smaller?
is playing mp3 a good idea on a 6600 at all?
mp3 file compresser?
I'm not aware of software that can compress an mp3 further though I am sure there is something out there.
Alternatively if you have the original CD instead of ripping at 128Kbs or 192Kbs which most people use, try 64Kbs instead. You may find certain rippers can also rip only in mono. This should give you a much smaller file than your standard .mp3 and the quality difference probabaly won't be that noticable on a mono mobile phone anyway.
http://www.dbpoweramp.com/dmc.htm
Totally free and very good quality
This has been discussed here:
http://www.allaboutsymbian.com/forum/showthread.php?s=&threadid=19569
try MP3Minimizer