I've learned of a couple of new possibilities since this thread began:
*
http://fritzing.org [more for the beginner and/or hobbiest, but really cool!]
*
http://www.pcbfx.com/main_site/pages/start_here/overview.html [do-it-yer-self -- but, no plated-through holes or masking]
* CircuitWizard has PCB design [that I have never used, so I can't vouch for it's functionality]. Circuit Wizard is great as a tool for learning electronics, but it is severely limited: Only basic ['90s era] components, no voltage regs below 5V, no LDO, no LM317, 4000 series only simulate at 5V, the part number list for active discretes, such as transistors is sparse [no PN2222A or PN2907A or modern MOSFETs], and no shottkey or fast recover diodes (you can create your own components but they won't simulate.]
* Check out BayArea Circuits "weekend warrior" special:
http://store.bayareacircuits.com/weekend-warrior-special/