This looks like a useful utility.

[ThomasKaira]

Vroute.info

Available as freeware.

It is linked directly to VATSIM, contains a huge database (70000+) real-world airline routes, and shows you exactly who flies them. 8-)

Navigation data provided by Navigraph.

[zacharace]

Excellent utility, especially if you shell out an extra $30 for the "premium" version. Fuel planning, current AIRAC routes with export, servinfo....I could go on and on