What exactly is the Thumbs.db file that keeps appearing in my site folder? Can i delete it?

It's a database for cached thumbnails in folders. I turned it off a long time ago, go to

Go to your Windows Control Panel, double click Folder Options, click the View tab (at the top), scroll down and find "Do Not Cache Thumbnails" at UNcheck it. It's right above "Hidden Files And Folders".

HTH.

is it OK to get rid of it? nothing will really be affected?

Nah, it won't effect anything, I forgot to say that you had to CHECK it not Uncheck....sowwe!

Thats helped me too, i always wondered what it was...i have thumbs.db files all over the place!