Is there a way to work with Netbeans and Github, synchronize them
Github plugin for Netbeans or something
Update
NetBeans 7.0 now has native support for Git at some level of functionality. It is available from the "Plugin Portal" Update Center (Tools|Plugins, then "Available Plugins").
See the NetBeans Git Integration Plan for supported features and a development roadmap.
There is a git plugin for NetBeans called NBGit. Note that it self-describes as experimental. There are links at the NBGit.org site to its Google Code project, and it appears that the actual source code has moved over to its GitHub project if you're looking for the bleeding edge. Development activity on the project appears to be thin and sporadic lately.
I've used NBGit several months ago, and found it to be a fair start, but not feature-complete enough to use for my day-to-day work. As mentioned in a previously-asked question, there are several basic commands missing that you need to go to the command-line or a dedicated GUI for.
It appears that NetBeans version 7.0 may include some level of native support for Git. Note, however, that the 7.0 planning document (first link in this paragraph) says "GIT support, in early access, AU only (preview)," which may mean that 7.0 will only contain a basic implementation like NBGit, and that we may have to wait for 7.1++ for feature-complete support.
Note that there is nothing special about working with Git repositories on GitHub. GitHub simply hosts the repositories. Any proper Git client can access repositories hosted there.
(On the other hand, GitHub does have it's own GitHub API to access the features specific to their web site / web app. That would be something different than working with the repos through an IDE though.)