You have a 56Kbps pipe, you are running dialup, that's the problem.
So I don't get accused of trolling, I'll go into further detail about how your use of things like FasterFox won't help a jot.
Most people's internet connections are about 1Mbps (I find), my connection is 24Mbps, yours is 0.056Mbps. That's like saying most people have a dual carriageway, I have a 12 lane freeway, you have a path created by a goat walking backwards and forwards across the same field enough times.
Fasterfox creates multiple connections and then drops all but the fastest one. This is like saying that if you want to deliver a letter to someone, you put a letter in each of a bunch of cars and send them all down the road and which ever one gets there first tells the others to not bother any more. This works well for me with my 24Mbps connection (my huge freeway) because the cars all fit on that freeway. It works ok for people with their dual carriageway, no matter how many cars you try to force down your goat track it won't work, the problem is not how many connections you have, it's how wide the road is.
Upping the priority on Firefox is like getting faster cars, you
still aren't fixing the problem of the road being too small.
When you get a delay before data comes through it's probably DNS resolution. The internet doesn't work off names like
www.google.com, it works of IP addresses like 66.249.89.104. Because we can't remember IP addresses easilly when you type
http://www.google.com into your web browser your computer looks up that name and gets the IP address it's going to connect to from DNS which is like a phone book of names vs numbers. This will take a few seconds on dial up to do, you can't avoid it.
It's 2006, get rid of dial up and buy a decent internet connection, it's not worth the time, money or effort to try and think up ways of getting the most out of a dialup connection.