Changing domains was a big decision. My biggest concern was being able to keep my user, RSS feed, and search engine traffic. Luckily, the power of the .htaccess file allowed me to do so:
Options +FollowSymLinks RewriteEngine on RewriteRule (.*) http://yournewdomain.com/$1 [R=301,L]
The above .htaccess file code, placed on the old domain, redirects the user to the same URL on the different domain.
Quick, easy, and functional.
One of the web components I've always loved has been Facebook's modal dialog. This "lightbox" isn't like others: no dark overlay, no obnoxious animating to size, and it doesn't try to do "too much." With Facebook's dialog in mind, I've created LightFace: a Facebook lightbox...
As much as developers now loathe Flash, we're still playing a bit of catch up to natively duplicate the animation capabilities that Adobe's old technology provided us. Of course we have canvas, an awesome technology, one which I highlighted 9 mind-blowing demos. Another technology available...
As you may know, HTML5 has introduced several new input types: number, date, color, range, etc. The question is: should you start using these controls or not? As much as I want to say "Yes", I think they are not yet ready for any real life...
I work with an awesome cast of developers at Mozilla, and one of them in Daniel Buchner. Daniel's shared with me an awesome strategy for detecting when nodes have been injected into a parent node without using the deprecated DOM Events API.
One more note. I recommend keeping your old domain for at least a year. Make sure to give users and search engines time to update.