At last year's Macworld Expo, I discovered HoudahSpot 2, a tool from Houdah Software that adds power to OS X's Spotlight search facility. In particular, I liked that HoudahSpot allowed me to add columns to the search results, something you still can't do in the 10.5 version of Spotlight. With Thursday's release of version 2.3.1, HoudahSpot gains new capabilities, a welcome appearance change, and a 15-day trial period, and a new $25 price point (down from roughly $30 before). Previous trial versions of HoudahSpot were restricted to 20 searches; the new time-based trial will let you get a real feel for HoudahSpot's abilities before making a purchase decision.
Version 2.3.1 adds full support for Finder labels—labels are displayed by name, and you can run searches against Finder labels. (Version 2.3.1 also has a minor bug that shows red-labeled Finder items as orange, and vice-versa. This will be fixed in a minor update that should be out any day.) While you won't see the actual colors within HoudahSpot, you will see the name of each color, which works nearly as well. I use colors to organize certain types of documents, and now I can find those documents within HoudahSpot.
Another new capability in the 2.3 series is BlitzSearch, which is a menu that drops down from the main menu bar, and can be activated from anywhere via a user-defined global hot key (as long as you have the HoudahSpot icon in the main menu bar). This makes using HoudahSpot basically as easy as using Spotlight—just hit the BlitzSearch hot key, enter your search terms, and off you go. BlitzSearch will find matches based on file name, content, and file comments (you can turn each on or off individually), and you can specify a HoudahSpot template to further refine the search.
The welcome appearance change is visible in the accent color used in the section headers in HoudahSpot's interface. In prior versions, the chosen color was a very vibrant shade of yellow, which was not to everyone's liking. In this version, the default color is now a lightish shade of blue, and you can choose from gray, green (my favorite), and red, in addition to the original shockingly-bright yellow.
For more on HoudahSpot, read my review of HoudahSpot 2.0.8 from last February.