[Identifying files inside a cluster]

I have been looking for this feature ever since I started using defraggers back in my Win95 days. This would improve the usefulness of Defraggler immensely.

[What type of Firewall do you use?]

I actually like the nVidia software firewall that came with my motherboard, called ActiveArmor Filewall. It has per-application allow/deny lists and automatically determines if software has been changed since being granted access, and ask again to allow it. Also, it doesn't have a built-in whitelist, so it won't automatically allow those stupid quicktime updates etc.