When you get a problem with a site .. say 32bit.com
open up a dosprompt [am assuming u are on Win9x] and do a tracert to the site ..
tracert http://www.32bit.com
you should be able to get a rough feel for the network addresses your packets travel through .. look at the resolved names and you should be able to get a decent idea on where the problem is ..
say you are a subscriber of diallup.com for ur internet
and you get something like
icecream.diallup.net etc etc .. and you get astoundingly long delays at those nodes then its obviously a prob with your ISP. Somewhere in the middle would mean its a problem with the backbone or a routing issue. and towards the end would mean the problem with the site u are trying to connect to.
Now you should also note that u neednt get an acknowledgement/time from a server becos it would be configured not to respond to your tracert. Again its just a generic solution but with intuitiveness it should help you.
The fact that u are getting quite a few sites that arent responding, i'd assume that its a prob with the ISP or the immediate route from the ISP. either way a call to them should do wonders.
As an alternative .. u can try
http://www.visualroute.com .. go to the demo and u can get a grafical concept of what i mean. uses the same theory as with tracert