Unfortunately, [[NSApp currentEvent] modiferFlags] can’t be used to determine if any modifier keys were held down during launch. To accomplish this, it seems one must delve into the world of Carbon.
Modifier flags during app launch
Google Subscribed Links
Google Subscribed Links allows users to subscribe to XML documents provided by websites. If a subscriber then searches Google for a keyword that matches an item from the XML document, the item is displayed at the top of the results page, and highlighted.

I wrote a plugin for WordPress that allows you submit your RSS feed to Google Coop.
Quicksilver Smoke
I wrote this a while back as part of the Quicksilver Internal Commands tutorial. The plugin hooks onto the current Quicksilver interface so you can watch it go up in flames.
Speed Cache
Another WordPress plugin. I’ve been using this on my own site for a long time and, after people encountered 404s searching for it, have decided to publish it.
Speed Cache basically takes external files such as javascript and CSS and mirrors them on your own server. I’m not going to go into detail about why you’d want to do this - you either do or you don’t. If you do, then feel free to use the plugin.
Support questions in the comments for now, but I’m not providing any guarantees. This post may be replaced by a proper info page about the plugin sometime in the future, but at the moment that’s unlikely.
CTGradient code bloat
While getting rid of extraneous junk in an application package is easy using Trimmit, the only way to prevent "code bloat" (and accompanying excess RAM and CPU usage) is through good programming practices. Where most developers fall short is in poor optimization of borrowed code. Let’s take CTGradient as an example as it’s well known and used (or more accurately, abused) in dozens of applications.
IconGrabber
I often need to use OS X icons on the web. Unfortunately, it’s not an easy matter to extract icons from Mac files or folders. The solution? IconGrabber.