Custom Blocks

If you're interested in Java and webapps both, JSP might be up your street. It has died a death fairly badly in commercial terms, but there's nothing stopping you grabbing Tomcat and playing with it. You'll probably learn better habits than PHP will teach you.

I can also strongly recommend getting good at embedded programming, though in most cases you'll be using a high level language like C/C++. Being able to write for memory constrained devices is a skill that's very much in demand, and sadly rare. If you want more serious playtime, I can heartily recommend buying a Chumby One. It's cheap, fun and is documented and hackable right down to the bare bones. It runs one of these and has nice handy pads for attaching an RS232 port to.

I would love a Chumby, but the paranoiac watches my bank accounts and I cannot buy one with cash.

Hah. Clearly you need a pre-paid debit card for all your money laundering needs.

My university issues one to all students. The problem is putting money on it. All transactions have to be explained to her. Or else.