First off, here's an idea for a new FA default skin! If it wins, I'd called it "Leopards Totally Pwn Hyenas."
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Anyway, seriously, I think the way Private Notes are handled is a pain. I admit after I read one, I sort of forget it ever existed and so if I don't reply right away, the chances of me rememebring to later are slim...Also, it's sort of a round about way to get to them if I have no new ones. Not really sure how to fix this without making it all too extensive or obtrusive, but just something I've had a headache or two over.
Making the Commissions Tab an option, off by default, would be fabulous. Also, I think it needs a little more work to be functionable--perhaps a way to upload a couple "portfolio" pieces to it (ArtSpots has something similar, you can pick your 5 "best" works to display on your main page. If in the commissions tab, you could display some samples of past commissions, it would be nice.)
Also, it's been said but more options, even just a thumbnail of the "examples" would make it a lot more useful.
Personally, the only "tab" I'd add other than one for screen caps/Second Life would be something for gift art or trades from other people. They could automatically upload like "scraps" so they don't show on the main page and possibly double spam.
Along the same vein you could have a tab just for commissions, but since a lot of people who dont draw upload commissions, as opposed to artists who upload their own art AND trades/gifts etc, maybe just making commissions "flagged" as "not my art" would be the best solution.
Lastly, how about letting us write HTML into journals? ;] It'd be nice to link to something without have a huuuuuge string of a URL. Could even be FA specific, something similar to the user icon tag :iconUSER: -- I know I for one sometimes link back in my journal to older pieces on FA that are either for sale, or have limited prints, etc.... though, HTML tags in journals would be for the win.