Just confirming everyone else's post, im already past this problem since i installed area51's cyanogenmod 7 precedent rom (ext4 class10 sdcard partition). The first thing i did though, root my phone, dl link2sd, and partition sdcard per link2sd instructions. No more internal memory problem. that was when i had a class 4 sdcard. It worked pretty well. When i changed roms (several times) i found that link2sd was no longer neccessary. Its built in to most custom roms. Yet with my class 4 sdcard things were agonizingly slow. I switched to a bigger class 10 sdcard, formatted my sd-ext partition to ext4, and bam. Fast, huge storage, the only other thing i tweaked which seemed to help was changing my read_ahead_kb from my roms default 2048 (stock is 128 i think) to 3072. After much read/write speed tests 3072 gave me the highest average read speed, at least for my card and my phone. Someone elses might be different. So, i think you either have to root or deal with low memory warnings all the time.