Take a look at how Feynman did it: http://www.physics.ohio-state.edu/~kilcup/262/feynman.html
Now, learn some new programming language (see some options at http://rosettacode.org/wiki/Language_Comparison_Table) and start playing again!
Also, write down ideas for projects that you would like to do. It might wind up longer than you excepted very fast... and as bonus, you'll get to learn new algorithms, programming paradigms and so on.