Has anyone played with WBB3, Virtual Breadboard? If so, I would like some comments. It is a free designer/simulator, much better than Fritzing. www.virtualbreadboard.com
aviator
Looks promising.
I'll give it a try!
It does indeed look promising. But I could use some help figuring out why it won't run when I try the tutorial for scratch creation of the Blink project. The one built in as a demo runs just fine. But when I try to scratch build the exact same project and get to step 7, once I load the Blink.pde source code file into VBB it "stops responding" and crashes the program. It does this on both WinXP and Win7x64. If anyone can tell me what to do to fix this I would really like to know.
Is it possible that there is something wrong with the Blink.pde file I am using? I copied it from the actual hardware project I built when reading the Getting Started With Arduino book, so I know it runs that project OK.
In stumbled upon the software some seconds ago, I´ll test it the next days... The video looks very promising to mee, I am an absolute beginner...
Post this, to bring the thread a little bit up again for the other beginners here... 
I've had no problems running the simulation of the Blink tutorial in a previous version I tried (4.2.9). I can't test it in the current version anymore because it now says runtime simulation is only possible through subscription. Can anyone confirm this? I have no problems with commercial (or close source) software, but in my opinion VBB is not mature enough to spend money on, even if it's just 10 dollars a month. I'm also a beginner and still looking for a good simulator. You can supposedly run .elf or .hex files in Proteus, but it's very expensive software. The best free way to simulate would probably be to try and run the compiled C-code in Atmel's AVR Studio. Haven't had time to test that out, though.