I have just about finished a new AJAX tutorial that teaches you how to create a Google Suggest style search box. The article walks you through the steps for creating the front end, making the AJAX request, and a simple backend that can be easily extended. Suggest is one of the better AJAX patterns that I have seen as far as usability is concerned. You can find the AJAX Suggest Tutorial here.
I have noticed there is a lack of really good information out there explaining how to use the Indexing Server, so I decided to write a series of articles explaining how to use the Indexing Server in several different scenarios. There are some really cool things that you can do with the Indexing Server from a website including creating, deleting, and rescaning catalogs.
I have also finished a rough draft that explains how to run IXSSO Queries from PHP. I will also be covering how to query the indexing server from .NET with the native CISSO wrapper.