indeed it doesn't matter how much you put in the phone, i tried my psp's 8gb stick in my old K750 and it works. it just doesn't show the free space correctly and it was kind of slow opening my mp3 folder (wich contained around 1000 songs) but still it wasn't irritating. i now have 512MB in my k800i i don't buy more because i don't need more. just some themes, pics and ringtones is all i have. i use my ZEN for music :p