MAC-MAN  After testing this out on just a few of the features... well I'm impressed. Personally prefer something a little simpler but boy this does it all!

Can't beat the price either.  
(Version 1.9.6b4)

MAC-MAN  Not too bad. Could do with some work but all in all does ok-ish. I'll keep an eye out for this one.

I think the price tag is a tad high though.  
(Version 1.0)

MAC-MAN  Tried this thing but must honestly say I was not impressed. There are many free apps out there that are far better and do a lot more. Why he tries to charge for this is a mystery.

MainMenu, for example which is also featured on this site is 5x better and does a lot more including serious deep (and safe) cleaning. I personally don't find MacDust an 'oustanding' tool as the Developer states, but that's my opinion.  
(Version 2.73)