Thanks for your interest in ESB and Camel. I am sure you know they are based on some very successful Apache projects.
I believe the best thing would be for you to join the Apache communities at http://servicemix.apache.org/SMX4/index.html and http://camel.apache.org. Look for the Contributing links. You can join the mailing lists at Apache, help other users in the community, help improving the wiki documentation and even look at the jira and submit patches for known bugs.
The Apache communities highly appreciate patches and contributions in any shape or form and your constant involvement will get you recognition, possibly even committer privileges.