How is it that I cannot register a recently expired domain? The whois database shows it as expired and pending renewal or deletion. I was always under the impression that the day a domain expired it was fair game.
No, there's a waiting period after the expiration date before the domain will be released for new registration. I think it's somewhere around 30 or 45 days. During this period, I believe the original owner can still reclaim the registration. Others on this forum will be able to give you the straight scoop on the procedures and exact timing for all of this.
My advice is do not look for an expired domain until after thirty six days. Looking may cause the domain to be registered as a speculative maneuver. The owner of Godaddy has an interesting blog on a slightly different problem much akin to this one. I think it is hard for an individual to get hold of an expiring domain.