If you're a desktop guy, and MS based, learn some silverlight, it's very nice and also a MS-win7 phone.
If you're not, Javascript + JQuery is the way to learn for the client side stuff, you also need a server side language (python, ruby, etc).
If you're not, Javascript + JQuery is the way to learn for the client side stuff, you also need a server side language (python, ruby, etc).
Ruby or python is probably the best choice, and I personally favor python.