Actually, while ‘text’ may be used as a verb in the cellphone world, it has not reached dictionary status yet. Text, for all real purposes, is still just a noun.

So if you want to be grammatically correct, you would not say “I texted him” or “I texted him.” You would say “I sent him (or her) a text message.” Someday the noun ‘text’ may become a verb, but until then if you use it as such you are a grammaticaly pioneer.