Blackjackking: Good call on Hardy Nickerson. He should not only have been on the list, he should've been #2.
What strikes me about this list is that Joe Johnson is the only big-money disaster the Packers have had in the history of free agency. After that, it's a pretty big drop down to Nickerson, McKenzie, Maas, and Klemm. They contributed very little, but were not top-level free agents.
If you were to make a list of the best free agent signings by the Packers and put it alongside this one, the Packers would probably come out of it looking pretty good. I can think of six very good ones off the top of my head:
1. Reggie White
2. Sean Jones
3. Santana Dotson
4. Eugene Robinson
5. Desmond Howard
6. Don Beebe
After that, it's a sharp drop-off to players like Hannibal Navies, Sean Lendeta, Mike Prior, and Mark Clayton, but overall, the Packers are well into the plus column on free agency.
Here's a link to a list of free agent signings, if you want to see for yourself. I noticed that Hardy Nickerson is not on the list, maybe because he did not sign until August 24th, 2002, when preseason was well underway, so he did not fall into any of the categories listed in the article:
http://www.packers.com/history/record_book/results_and_rosters/nfl_free_agents/