I think the comment of Peter is the right one ... indeed it is the
job of SRS. Just stay tuned for latest news on SRS5 ...
About the features, I just wrote an applet that will become part
eventually of the SRS5, which is used to navigate in a user-friendly
way in the feature tables. It is part of the JaMBW project that I am
carrying on and that involves Java and Molecular Biology. Do not
miss it (http://www.embl-heidelberg.de/~toldo/JaMBW.html).