At about 12:56pm on 10/15/02, it was discovered that the solution to the ECCp-109 challenge is...

k=281183840311601949668207954530684

A brief reminder: The challenge consisted of two points, P and Q in the same simple-subgroup of a particular elliptic curve group. This is the value of k such that Q = kP. The announcement is being made now, a week later because the team had to wait for comfirmation from Certicom that this is the solution.
Update: Certicom has confirmed the solution! Congratulations all!

Seems like an awful lot of work for that number, eh? Well, it was an awful lot of work. By the time the participants found the solution:
The project took 549 days.
There were 10,308 Members and 247 teams.
Totally 68,228,567 distinguished points were computed (a priori probability of success at this level was about 0.64).
Totally about 36,507,222,000,000,000 points total were computed. If one person tried this himself, he would have needed about 4000-5000 PCs working 24/7 on this project alone, for one year.

Without a doubt, this is one of the largest single math computations ever completed (of course, it depends on what you consider a math computation to be.). It is almost certainly the most difficult discrete logarithm problem ever computed, and definitely is the hardest elliptic curve discrete logarithm ever computed (That we know of ;).

Source: ECCp-109 Challange Homepage