Mac Cleaner?

In Safari, you can check Private Browsing (Safari menu) to cover your tracks, other than that there are usually not many "unnecessary" files except for application preference files in ~/Library/Preferences, which are usually very small. What kind of files are you worried about specifically?

 

Yeah, Macs are inherently clean. However, you may be interested in Cocktail or Onyx. I don't use or condone either though.

 

In OS X, most applications that you install include all their files inside them. Therefore, when you throw out an application, its accessory files go with it. If the application was installed with an installer, that may mean there are files "around" in other places on your disk, and in that case you should attempt to use an uninstaller, however the majority of applications are "packages" or "bundles". What looks to you like a single file with one icon is actually a special kind of folder that can contain any number and types of files. Right-click (or Control-click) on an application and select Show Package Contents and you will see what I mean.

 

MacJanitor is freeware:
http://www.download.com/MacJanitor/3000-2274_4-10227094.html
OmniDiskSweeper is shareware, but a good Utilities App
http://www.omnigroup.com/applications/omnidisksweeper/
X

 

OnyX is amazing for the little bits

 

I really like(d) Onyx, but ran in to major problems during an update (back in like 10.3.5 to.6. I ran Onyx and hung, and went in to about a two day ordeal to get back to normal. It may have been just coincidental, but I've not returned to Onyx since then. Have you had good results up through 10.3.9? How is it with Tiger?
X

 

A lot of people like Anacron and it's discussed in at least this one thread.

 

Just tickabiboo

/camp