We'll respond shortly.
“How do I get the cursor to appear in Firefox after resizing a textarea?”
After resizing a <textarea> using jQuery with an animation, you can type in the <textarea> but the cursor is gone.
Ideas to try include resizing the <textarea> without animation, and try triggering a blur or focus event.
“Is anyone using underscore.js to add enumerable support with jQuery?”
Nobody here has tried it officially yet, looks promising.
Seeing this in Safari only which has a more strict default setting to handle same origin policy. If you load a page from your own site with an <iframe> with a page from another site, that other site is not able to set cookies, and is is a problem on one project trying to use Facebook connect in an <iframe>. The solution was to redirect the entire page to Facebook connect, and then redirect back, which is not an ideal user experience.