Something I've been wanting to do for a good while now. I'd like to bring your attention to this nifty addon which allows you to enable/disable addons without relogging.
http://www.wowace.com/projects/acp/It can save profiles and can be stored by class. Example for me would be a profile for raids with almost everything disabled and one for solo play which loads addons like gathermate or auctioneer. Especially handy when an addon needs to be loaded and relogging would take too long (patchdays).