I've always made it a habbit to scan anything other than mp3 files for virus's. There are alot of Back Door Virus's out there.

For example :

If you search for a program and you know its going to be a quite large program and you get search results of a file 187K then 9 outta 10 times its a virus. Its what I call a "CLONE VIRUS" it shows up in LimeWire of any search result.

Example: I search for Pinnacle Studio 10.5 Titanium - File size is 1.25 GIG - but my search results only show up exe files that are alot smaller. 9 out of 10 times it will be a virus or usless adware.