Jailbreaks usually do not have viruses.
In my opinion, sn0wbreeze is the best jailbreak.
Sn0wbreeze. Google. :D
Yes, using Sn0wbreeze. Just a google search will take you to the site.
Using Sn0wbreeze. A google search away from free apps :D
I've heard about Sn0wbreeze doing it but it is a pain in the neck doing it. This rumor might not be true. Just try Sn0wbreeze, you have nothing to loose. P.S. Most likely in like a month when 4.0.1 comes out there will be a spirit userland jailbreak for 4.0 and up will come out. Hopefully soon.
Depends on your jailbreak, For mine, (sn0wbreeze) Nothing bad happened It just turned back to a normal iPhone.
Yes, using Sn0wbreeze or others. Just search it on google and you'll probably be able to find it or another similar iOS 4 jailbreaker.
yes
Just google search, looking for Sn0wbreeze. Quick(ish), easy, and you get the free apps. Revised answer by Alexthegenius: You can also go to http://jailbreakme.com/ on mobile safari on your iDevice and just slide to Jailbreak. It's that simple.
get them slower and let viruses attack your system
you are probably tethered so if you used redsn0w open it on your computer and click extras then hit just boot and follow the directions. If yoused sn0wbreeze, run ibooty on your computer
For iOS 3.1.3 there are several options available. One of the top results you can find is a jailbreaking tool by the name of Sn0wbreeze. Look that up, download it and follow the prompts