I’ve been playing more with jQuery lately and enjoying it. It’s small, quick, cross-browser, CSS-compliant, and won’t conflict with any other javascript libraries (including ASP.NET AJAX). There are also a number of easy-to-use plugins that offer some nice almost-turnkey functionality w/ a few lines of javascript (e.g. tabs!).

There are other powerful javascript libraries, like prototype, script.aculo.us (which uses prototype), dojo, mootools, and a bunch of others.

It’s tough keeping on top of everything in web development, since there are new tools and widgets all the time. Spend too much time checking out what’s new and you never learn anything in depth or get anything built. Spend too little time learning what’s new, and you miss out on huge timesavers and risk getting outmanuevered by speedy web 2.x competitors. So I try to maintain a balance, and drink a lot of coffee. 🙂