Creatine definitely helps me do a few more reps. It has a noticeable effect on my strength, that remains for a while even after I stop taking it.
One thing I need to add: I don't understand why people still take creatine monohydrate when there are non-monohydrtate forumals that don't cause bloating available. Creatine monohydrate bloats the fuck out of me, to the point where my abs fade, and I lose a lot of the definition in my face. In short, creatine monohydrate will make you look like a fatass, even if you are ripped, because of the massive water retention it causes. I take a non-monohydrate forumula (containing creatine titrate, I believe), and it causes no subcutatnous water retention. So unless you want to get all bloated up like a fucking blowfish, avoid creatine monohydrate at all costs!