Odd internet behavior. Any ideas?

Sounds like a problem with port 80 only. Is your email app working?

I don't use an email app, I use gmail (online)

Happening with anyone else or just you?

Most people I've talked to have had this problem

honestly i havent had any such problem
but you could try using a proxy and see if it helps (since i have heard stories that some colleges want to limit internet access)
Also since you are chat is working you could try using a chat application that also lets you browse the internet like TEN Chat Browser

sounds like a network issue. Have you checked with the IT section

Eh. Our It section consists of one guy who has read some stuffo nline a couple times.

Firewall or antivirus maybe blocking ports?
(idea inspired by 1st post from glial)

Simple things first, I would reset all the switches and restart the the DHCP server.

I don't have access to these things....I'm just an end user on this network.

It could be a problem with Internet Explorer and/or cookies issues. You might be able to change the settings in the control panel under Network and Internet connections. Firewall would block also.

I'm in firefox but when the problem occurs, none of my browsers work

DNS issue? Maybe your school's DNS servers are down so you can't resolve URLs to IPs. Or perhaps they updated the DNS servers' IPs so you're no longer mapped to them.

Can you access fluther if you type 208.70.
150.41 in your browser's address bar?

Sorry for the accidental line feed. Should have been 208.70.150.41