-Dsun.java2d.opengl=true (use True instead for verbose output informs you that the graphics pipeline is open)
Which sketches will benefit from such acceleration could be determined empirically, although this article gives some guidance. I was alerted to this information by one of phi.lho responses (on the processing discussion board) to a query about relative speed of some sketches on Windows and Ubuntu (which were different Ubuntu slower, until the use of this java option).
This article is only of interest if you've got a decent graphics card and are not using software emulated graphics acceleration (eg mesa on linux). Doesn't seem to play well with control panel sketches such as jwishy.