General Tips and Tricks
OpenAjax gives ajax guidelines
Use the # to maintain state within your app.
Push Data to the Cloud
Because users are starting to access the web through multiple devices, there is a need to modify your application to run in the different contexts. Kevin Lynch showed a music library application that accessed his person music through the computer, phone, and Wii.
Manage Large Data
Charles Kendrick had a lot of good ideas on how to sort and filter high volume dataset. The idea is similar to chunking data. When a sort needs to happen, push the sort back to the DB if the record count is larger than the client page limit.
Complete Server side Solutions
One technique to do partial rendering of pages is to keep track of the DOM tree and perform a Diff between the two DOMs. Then send down the Diff file to have the client update the parts that need to be updated. Very clever.
Use a publish subscribe bus on the client for inter-component communication.
Variable User Experience