[FightCube] wrote in recommending a very helpful piece of circuit simulation software for those of you still constructing entries for the 555 design contest. LTSpiceIV, available from Linear Technology, allows you to construct moderately complex 555 driven circuits including common components such as capacitors, resistors, diodes, FETs, and more. Once you have constructed your circuit, you can view the results in an easy to use visualization window, without ever having to touch your soldering iron or a breadboard. According to [FightCube], the software is fairly easy to use, and best of all, it’s free.
He has shared one basic circuit he built as a demonstration of the software’s capabilities, and promises to share more in order to motivate others to enter the contest.