I'm doing something similar to the following post: Need Help Creating an Edit Form.
I'm essentially working on creating a Graduate directory for a Yoga College and I want them to be able to login (I'm currently using WPMU Dev's Membership plugin) and edit their profile at anytime they want. I'm already aware of the Gravity Forms Directory + Add-Ons plugin, but it doesn't work exactly as I'd like and would prefer to do it myself to have better control over the display/output.
Finally figured out how to get the user's entry without submitting the lead through a query var. Posting here for other people that may need it. Important things to note: this code is for a form locked behind a membership gateway which means that the person has to login to access the form ($global $current_user; and get_currentuserinfo() won't work for non-members). I also set the "e-mail" field to be unique so that the person couldn't accidentally submit more than one copy of the form.
Pastie has full code here: http://pastie.org/3018442