they
Care to elaborate? ISP, school admins, Chinese internet police, mafia family from Palermo, or perhaps you meant
THEM!,
THEM, or perhaps even
Them! or
Them.
...ah, too slow, so your school admins decided to do... WHAT?

It's time to call in the heavy artillery, methinks. Before retorting to A-10 CAS flights sweeping those blocks away.
I don't really know what's going on and where, but if its not something too sophisticated, you should be able to enter the forums from, say,
proxify.com, and you might also want to take a look at
XeroBank Browser which is essentially Firefox with a twist that makes it connect the host server via onion networks that effectively mask IP's here and there, which means that even if HLP/GW server for some incredible reason is blocked by the ISP, it should be circumvented by XeroBank (previously known as Torpark) because the data doesn't really seem to be coming from HLP/GW server. And, the great thing is that you don't need to install XeroBank on your PC so you don't need admin rights. You can run it from, say, USB-stick. Or your home directory, which works somewhat faster.
It's slower than regular browsing, but should work to some extent...
If it's browser specific filter/limitation, you might want to use a
portable Firefox installation without the XeroBAnk's Torpark connection system.
...of course, all this applies on your school's Windows PC's. If they only use Unix, your last best hope would be proxify.com, but I wouldn't hold my breath there. And uploading/downloading files via that would not work (apart from those text files [tables in this context] that can be copy-pasted).
...Why are they doing this?
And don't you have net connection at your home?
