One project, 2 CVS servers ?

[FP]

I've been using CVS for several months, and I find it really usefull to 
keep in sync my projects between my work, home and notebook pc.

Now I want to take part in a project hosted on sourceforge. I want to 
make radical code changes in some areas for testing pourposes. I have no 
write access to the sourceforge repository so creating a branch is not, 
at the moment, feasible. And of course I'd like to use my private CVS to 
store changes and for syncing pc and obviously merge from the 
sourceforge trunk when necessary....

Pratically, two servers for one sandbox......

I want to add that I have full control on my CVS server and I can run 
any command on it, if necessary.

I know that I can export the sourceforge trunk and import as a new 
software version and then reapplying the diffs... but it is a time 
consuming and error prone work...

Any ideas ?

Thank you,
Francesco

PS: I'm also looking for articles/books/blogs/any written texts about 
CVS usage filosophy and "best practices"