no, just check your phone if it takes Micro SD cards most phones do, there is probably already one in yours now (maybe 1GB 2gb), open it up..... I doubt they take the larger standard sized cards (like bigger than postage stamp size)
Gee! Wonder why AT&T doesn'talready have a micr sd card in/ w the LG Optimus? I bought mine @ 1 of the AT&T STORES too! Thanks for the extra info,though. ;-(