Interestingly, Niven’s character Lous Wu deals with the addiction aspect of wireheading by having his device only work after a timed interval since the last hit (this can be overridden by the user, but is deliberately made very fiddly to do).
Wasn’t it also Larry Niven who said the device would be a great aid to human evolution? To wit, the people stupid enough to wire themselves for continual pleasure would die out, removing their stupidity genes from the gene pool…
Niven has some funny (and erroneous) ideas about evolution (ref. the “luck gene”); rjung. If what he said about the pleasure device were true, then generalizing from it, there would be no one today who engages in any risky behavior.
Slightly off-topic, Devilman Palmer, but your username alone sounds like a pleasure device to me. 
Why, thank you. 
Naval sex.
Personally, I wouldn’t want anything like that, it would make me to anxious before pressing it. What would be cool though is the ability to vary the intensity and build up.