Second Life Connection Troubleshooting Advice
Trouble connecting to Second Life? I know, who doesn't have trouble? Nalates Urriah has exhaustive and immensely helpful troubleshooting advice. Here's a nugget about testing the connection between you and Linden Lab's servers in San Francisco:
SpeedTest.net will let you test your Internet connection. Run it at its default settings or point it to San Francisco, USA (SF). If you have good numbers now, point it to the server name or IP address you got in Help (or the one above) and try the test again. If you get bad numbers to SF, the connection problem is you or somewhere in the middle.
Much more here. Amusingly, I can see the general location of Second Life's servers from the windows of my San Francisco apartment (about a three miles away, in the South of Market area), but somehow, that proximity doesn't help my connection much.