My company participates in the IOA Corporate 5K, which is a huge event with hundreds of companies and nearly 7000 participants. Last year due to a screw up, I didn't wind up running on my company's team, and neither did a few others. This time we got on the right mailing list and didn't have that problem.
Companies can enter men's team, women's team, mixed teams, and also have walkers, so the idea is to show up, hang out at a tent, and enjoy the beer afterwards. ;) Each company gets to have 5 "seeded" runners, people who are expected to finish in the top 10% or 20% overall, with a different colored bib number which lets them line up at the front. I didn't have a seeded number, since the team coordinator was going to finalize that at the event depending on who showed up, but a friend who often works at running events - I think she works part time at Track Shack, a local shoe store also involved in producing many events - saw me beforehand and gave me a seeded number, which was orange instead of blue, and let me line up ahead of about 6800 other people. Cool!
Anyway, I haven't been doing much speed work but I have been biking and running regularly so I felt like I could do between 22 and 23 minutes. I finished at 22:11 which I was extremely pleased with. I even took mile splits and they were reasonably consistent - I ran the first mile ~10 seconds faster just to help separate from the crowd.
Our men's team came in 3rd in our division, and 7th since we had enough people to enter two teams. The women's team came in 1st in their division, and the mixed team came in 3rd. Overall we did really well as a company!