You can jailbreak your PS3 with one of the following methods:
1. If you are on OFW 3.41 and want to remain on 3.41, then JB your PS3 with a dongle or any other device cpable of doing so (search on this site for methods to JB your PS3)
2. If you are on OFW 3.55, use a CFW by Kmeauw (there are other CFW's, but it seems that this one is the most stable - also do a search on how to do this)
3. If you are on OFW 3.42 or 3.50, decide to upgrade to 3.55 or downgrade to 3.41 and do either 1. or 2. above (search and read up on the downgrading your PS3 if you want to downgrade)
Hope this helps.