There are many flavours to the AutoComplete implementation, I first did a WPF implementation that was very robust, each entry took keywords, so when searching for an employee, it didn't matter if you typed the first or last name, the results came back similar to Google Suggest.
What I have found limiting in both the JQquery autocomplete and the ASP.Net Autocomplete extender is that there is no keyword search, or contains functionality, it simply uses a "Startswith" type search.
For example, in order to Search for "Mark Adams" as a staff name, you have to type in M,a,r, etc. If you typed in A,d, etc, no result would return.
Does anyone know of plans for this? Is there anything out there right now?