So if you are on RHEL5, and you want to upgrade to the latest and greatest version of Snort without compiling, see Vincent's RPMS.
Sourcefire, however, makes no endorsement of Vincent's RPMS or their contents. Use at your own risk. Sourcefire will always recommend that you download and compile Snort, from the source code, available at http://www.snort.org.
Take a look:
http://vscojot.free.fr/dist/
Hopefully this will help those of you at RHEL5.
UPDATE: We created a page at Snort.org to help you if needed.