Large File (Chunking?) http uploads via proxy server?

[freebsd]

Pardon the off topic question, but one of the things I like about this 
list is the varied skill set everyone has!

I need to upload large files via HTTP throught a proxy server.   These 
files can be multiple GB in size.   I realize FTP or SCP would be 
superior - but the proxy server does not permit those protocols, and I 
don't control the proxy server.   It is possible (in fact gotomypc does 
it somehow in their product).    Most upload scripts load the entire 
upload into memory - clearly this is not suitable.

Thoughts?

Paul