You're probably safer than with a PC... although the browser is not fully functional yet so while I find it useful sometimes its not the best browser out there by a long shot.

ok seems like I'm safe with the PS3 browser but I also have Yellow dog on my PS3 can I get a virus through that and would it effect my PS3?

about linux generally its to say that you are relatively secure too, but there allready exist a few rootkits which allow users to gain controll over linux computers (mostly limited to the pc platform again) that are not using the newest security patches, and then abuse these linux computers for spreading spam or (windows) viruses.

but for now the best security on all consoles is the special hardware architecture on which no pc virus natively can run, and their relatively low number when compared to all windows PCs  that often are much easier to infect. This means Windows pc's are still the main target for virus programmers, but that does not mean that there is no chance that ever someone will write a virus for ps3 (or any other console), it might still happen especially when one of tehse platforms gets more and more popular in the internet.

Another bonus of the limited platforms on consoles is that aoll ps3 geenrally run the same os software version on the same hardware (only small differences), so its easier to fix the security leaks the viruses used with firmware updates.

Its safe but slow. I dont use it.