The "Bringazz a Munkaba" contest has been going for a few years. Check out an English-language description of it here. I participated when it was last held in the spring partly because the contest website promised a free gift for all participants. Noting that the sponsors ran the gamut from Merida bike manufacturer to the Flora margarine brand, I half suspected my free gift would be a tub of butter substitute. But several weeks after the contest's conclusion, I was pleasantly surprised to receive an envelope containing a certificate of completion, a bandana printed with the T-Mobile logo and a useful reflective band (pictured).
Anyway, the contest is very simple. You register on-line at http://www.kamba.hu/ -- you can do so as an individual or as a group -- and you write down how long your regular commute is. Each day you commute, you check off on your account calendar, and the site automatically tallies your cumulative kilometres. The way it worked last time was that you could retroactively tick off commuting days up to three days after the fact. But if you let it slide further, you lose it.
I did pretty well last time as I'm commuting virtually everyday from Budapest to Szentendre. But there were people with even longer commutes that that. At least in theory. The contest works on the honor system so you can cheat or stick to the straight and narrow at your pleasure.