Eclipse/CVS - can I stop some files from being CVS-ed?

I've been trying out Eclipse's CVS integration using one of my projects at home. I've set up a CVS server on a spare Linux box, loaded my project into Eclipse, checked it all into CVS, made some changes, and checked in the changes.
In general, I really like it. It's smart enough to catch all the changes I made, including adding a new file. All in all, pretty painless.
However. I have now realized that Eclipse has checked in every file in my project area, even though several are actually duplicates, temporary files or output files rather than actual source code.
I'd prefer not to check in all of these temporary and duplicate files every time I check the project in, so does anyone have any suggestions for a way to allow these files in the project area, but tell Eclipse that they (and in most cases, the directories they live in) are not to be version-controlled? I'm willing to delete the version on the CVS server and re-"share" the project if that would be the best way to do it.
All suggestions welcome. Thanks.

It should be okay to just add them to .cvsignore (an option for this should be somewhere in the context menu when you select a file).

Thanks for that. Thet's helped a lot.
Strange, though. I could do it for quite a lot of the files, but for some the option is always "greyed out".
For example, I build my prroject using Ant, and the junit task spits out a file "TEST-tests.LocalTests.txt" in the top of the project directory. This file is wholly transient and there's no need to keep it under version control, but Eclipse doesn't seem to want me to ".cvsignore" it.
Any idea what I'm missing?

Two cases come to mind:
- it is already cvs-ignored, perhaps by a wildcard-entry in .cvsignore
- it is already shared in CVS, which makes it impossible to ignore. You will need to delete it manually from the server before being able to ignore it. This is one of the weaknesses of CVS...
BTW, make sure you have Window/Preferences/Workbench/Label Decorations/CVS enabled...

Thanks, Ilja. I'm sure it's the second of your options. I'll look into deleting it from the server some time.

You're welcome!
If it is already in CVS (and the label decorations are activated), you should see either a small yellow thingy (no changes) or slightly bigger black one with a yellow asterix in it (local changes) at the right bottom of the file icon.