plus flashing from the sdcard allows u to carry around a few xtra roms on ur sdcard just in case the rom ur testing/using decides to take a dive.if the rom ur tryin has too many bugs, too slow, or just plain unstable.then u can always reinstall one of ur trusted roms thats saved to ur sdcard.just open up FileExplorer and rename the rom u want to use to RHODIMG and ur set to flash again.but just a quick note;ive found that flashing from an sdcard works best when the sdcard is 2GB or smaller.Ive tried to flash from my 8GB and my 16GB SDHCcards and it does work,most of the time,but it tends too have more bugs and it seems like i dont get as quality of a flash as i do with micro sdcards that are 2GB or smaller.but thats just my opinion.i dont know it to be fact tho,just my experiance.Good Luck.