What are the most profitable ways for a programmer to make money from open source code?

As a programmer, I am impressed by the quantity and quality of open source software products. A couple of the best ones I’ve personally used are: jEdit and FreeMind. I support the open source concept, but am concerned that it negatively impacts programmers’ income potential. Becoming an open source consultant would probably be the best way of making a living from writing open source code. How else can a programmer make a living from open source code?
Some additional questions… Can one legally repackage and resell open source? Are there standard types of open source licenses?