There are quite a few options out there. I know people use VCB (provided through VMware), there is vRanger, esXpress and others. We use esXpress and really like it, but run 3.0.2 but many of their users run 3.5
Here are some other threads:
Hope this gives you some ideas
I'll second using esXpress on 3.0.2 and really liking it! esXpress has been very good.
I have palnned for VCB with NetBackup 6.5.2, with a physical Windows 2003 server as proxy server (Media Server)
Its seems to be the best fit for my infra. already have netbackup 6.5 in place.
it offer file level as well as full vmdk restore also.