Originally Posted by jumbb
If I'm using windows on my macbook using bootcamp, can I get viruses?
Bootcamp is just a way to create a dual boot system. When you boot into windows, your mac is just another Windows system with all of the usual security concerns. You should definitely run an anti virus application or full security suite, just like any other windows system.
Also, a Virtual Machine running Windows in VMWare Fusion or Parallels inside of OS X is still just a windows system, and the VM should also be protected like any other windows system. Parallels desktop even includes a copy of a security suite to be installed in the guest OS (not sure if Fusion includes one or not).
If your bootcamp partition or a VM does get infected, it's not very likely to infect the OS X side, but it is certainly possible that infected files could end up in any shared folders that the Windows OS has Access to. Having an infected file on your system is different from having an active infection - the issue being that you can become a carrier of a virus and pass it on to others by sharing the file (literally through a file share or as an email attachment).
Finally, just because Macs are touted as being 'virus-free', it's still a very good idea to run at least some sort of AV on the OS X side. This will if nothing else detect Windows targeted viruses that end up in your file system, protecting your friends more than you. ClamXAV is a free anti-virus program for OS X that is pretty light weight. Symantec and Intego make commercial Mac AV packages. I believe Sophos also has a Mac client that is intended more for corporate users. I've used Symantec, Intego and ClamXAV. I fell back to ClamXAV as the others seem to be resource hogs.