My wife Carol and I have been visiting family in Rhode Island this week and since our grandkids are in school on weekdays, I have had a lot of time to spend writing the fourth edition of my Java AI book and also catching up on reevaluating web frameworks.
Although my main skill sets are in data/text mining, general artificial intelligence work and Java server side development, I do find myself spending a lot of time also writing web applications. In the last few years, I have done a lot of work with Rails (and some Sinatra), GWT, and most recently with SmartGWT because one of my customers really liked SmartGWT's widgets. (Note: if you are in the San Jose area and want to work on a SmartGWT project with me, please email me!)
For my own use, because I have strong Java and Ruby skills, the combination of Rails, GWT, and SmartGWT works very well for me when I need to write a web app.