Techreport reviewed a 2.5" 8Gb Flash drive and performance is surprisingly slow, even up to three times slower than a 2.5" 4200rpm drive in some tests 
http://techreport.com/reviews/2006q3/supertalent-flashide/index.x?pg=1
http://techreport.com/reviews/2006q3/supertalent-flashide/index.x?pg=1