there's either something seriously wrong with me, either that or all you virgins have got the wrong idea....
It took me about a month with the girl i lost my V-Reg to before i could consistently orgasm at all through penitrative intercourse alone, not once was she ever able to bring me off with a blowjob or a handjob during our 10 month relationship (and before you say she was evidently shit, she's had many before me and many after). The one before that never managed to bring me off ever, 14 months of solo action only, not fun, however, she may have just been shit.
Another thing too, its not like its a bloody race, the objective is to enjoy yourself, not to spaff your load in the quickest time possible, or to hold on and deny yourself past the point of enjoyment for the sake bragging.
The other thing, the actual time always depends on my factors totally beyond my present understanding (i am but a young padawan).
So for the sake of completeness, i will list the shortest, longest, and my current of average (all rough estimates). All figures quoted as when doing these things only.
Handywork: 2min<- 5-10min -> "immune" (for want of a better word)
Blow job: only once has it ever worked by itself, that was when i was extremely horny for it, still took a good 5 minutes though, aside from that one time, i seem to be "immune"
Vaginal: i've totally misfired (spunked without orgasm) and splotched in about 30 seconds a couple of times, not sure why, i think it was stress <- 30-60min, a few 90min affairs -> "immune"
Anal: did it by itself once, for lack of a condom, it took about 10 minutes.
In response to barrington, I agree entirely, but thats all the more reason to practice, besides, 40 minutes is an awfully long time for a repetitive task.