Gar! Sorry, this annoying little bug crept in a few days ago, preventing only new users from entering flights (which is why I didn't notice it...). It should be fixed now, so please try again and let me know if it's still not working.

And yes, great circle routes are now implemented! Writing the code to render them was, if not exactly easy, then still rather less painful than I expected; getting it working right on IE7 had me tearing my hair out for a while though. I wasn't actually all that convinced about the importance of this, but now that it's done, I have to say it looks a lot better than before!

Right now, all great circle paths are rendered in "lo-res" mode, meaning one segment every 1000 mi -- looks OK in full-world view near the equator, but gets pretty choppy near the poles or if you zoom in. Up next, user configuration, after which you can choose no GC routes (fastest), lo-res (every 1000 mi, default), or hi-res (every 200? mi, slowest) rendering.

JerseyVics: The calendar shows only the last 10 years, but manually you can enter anything you like: anything between the years 0 and 9999 is fair game. Displaying future flights in a different color or as a dotted line is already on the to-do list.