Removing app's from context menus?

Hi,
can anyone tell me how OS X builds it's application lists? I'm finding that odd application are cropping up in context menus and it's bugging me something rotten. For example, right click on a file, "open with..."

Textmate
Textmate
Safari
Safari
OmniOutliner
OmniOutliner

I'm assuming this is because these application have been upgraded or deleted and reinstalled.

All of these also appear in, for example, the Applescript "where is the app..." dialogue. Last, and least, I want to kill all the evil batch job options that Photoshop gives me when I right click - open with on an image ("No, I don't want to convert this to a solarized 1x1 tiff, thanks....").

Any help would be appreciated.

Thanks,

G

That worked perfectly!

Many thanks,
G