MySpace has a good post explaining why you can’t use relative links within OpenSocial applications. If you’re building for the OpenSocial container and trying to make valid HTML apps, watch out for this one. I’ve written the following in a lot of applications and suspect that others have as well. The #na below will cause problems, despite being valid markup.

<a href="#na" onClick="doJavascriptCall();">Click Me</a>

Consider the following ways to invoke functionality instead:

<a href="javascript:;" onClick="doJavascriptCall();">Click Me</a>
<div onClick="doJavascriptCall();">Click Me</div>

I’m noticing an increasing number of blogs are no longer providing links with a commenters name. While in itself a downside for folks trying to make themselves known through commenting, it does seem a good way to cut down on spam. A tip for folks looking to self promote through commenting, be sure to add a brand to your username and have good content to link to.