Right!
I have been reading these threads and i have found many people have problems with viruses.
Here are my tips ( I have used Limewire for a while and have never got a virus)
1. Know what filesizes and types your are looking for are, CD ISO's are about 600-700Mb not 1Mb.
DVD ISO's are about 1.2 Gb
Installing EXEs are about 10Mb

2. As far as i know Video/Audio files are unable to be viruses (exept .wmf). And also, You can get 20 minutes of Medium Quality quality video for about 230 Mb, so look for about 10ish Mb/minute.

3. Get a good anti-virus / Firewall. I use Norton Internet Security 2006. It has a great firewall and anti-virus tool. Some files you download from limewire are viruses, and due to them mostly being in ZIP format can get through, so always scan them before AND after extracting.

4. Don't be stupid! Look at the file sizes, and arange your search by size, Click o the sizes tap TWICE so that the larger files are at the top, and wait 15 seconds or more untill you get a few results.

5. The filename. The file name also gives clues. Something like, Entr Drgn Brc Le.avi or Enter the Dragon - Bruce Lee.avi which one would you choose, Alwas choose filename that look like the have not been rushed.Also if you search for Simpsons and you find a result that is called S_i_m_p_s_o_n_s.*** It is not real, if you look at the file size you can tell that easily. Or Throbery Bob.avi and Throbery Bob (Amy Lee, Chuck Norris, David Tennant).avi the second one has a larger chance of being real.

Hope that Helped.