ICSI Netalyzr
Check out the Netalyzer from the International Computer Science Institute … it gives you all sorts of interesting details about your Net connection.
I just noticed, though, just before posting this link, that it’s “still in friends and family mode” and they ask you to please not spread this link.
Too late. I got it off of GMSV. Cat’s out of the bag, it’s already being spread.
Please be gentle with it.
[Updated Link - Thanks Nicholas!]
ITs not in beta. However, you need to go to the main link, http://netalyzr.icsi.berkeley.edu