Clean my Mac 2 is one tool (requires purchase). There was a recent review on
Mactalk about it.
Main Menu is another one I've used in the past (they have two versions at different prices)
Onyx is free if you want something you don't have to pay for and it does a lot of what the others do.
Unfortunately you just missed a macheist 10 apps for $9 special that incorporated clean my mac and a couple of other apps but if you're not in a rush to buy it, keep an eye out for discounted pricing which always happens on these kinds of sites. The other site that runs specials is macupdate.com. They have one app on special every day (50%-80% off) and every 6 months or so they run a major promo which includes 10-15 apps at about a 90% discount. Generally there is one major app (like Parallels) and a lot of smaller lesser know apps so I tend to keep an eye on them and if I want one of the apps, it's worth buying just for that.