PS2, not PSP... and wouldnt a mini PS2 have the same size cds so that all the games that have been released to date are compatible. Although, with my experience, burnt media will usually not play in playstations, burnt cds are simply a no go, and burnt dvds are a toss up.
If you want to listen to MP3s CD or DVDs, just get a cheap dvd player, you can even get DivX DVD players, my friend got a no namer for $100 CDN... and I got a Yahama DivX DVD player for $200 CDN...