Last time we traded down (last time I remember) we traded down from our first-round pick (26th overall) to get the Buffalo Bills' second- and third-round selections (Nos. 42 and 73 overall). So dropping 16 spots got us an extra third round pick.
Here is the draft value chart:
http://sports.espn.go.com/nfl/draft06/news/story?id=2410670
I'd like to do a similar deal this year and trade out of the first round by dealing our #18 to Cleveland for their #36 and #50 (maybe we have to throw in a 5th round pick to make it work). A trade like this would give us the #36, #49, #50 in the 2nd round and #84 and #97 (assuming we get the end of the 3rd round compensatory pick) in the 3rd round.
3 second round picks could be just what this team needs. I think we could pick up a solid wide out (Kenny Britt

If we left this draft with Britt(WR), William Moore(S), and Loadholt(OT) or their equivalents, I'd be clapping for JA all summer.
Thoughts? Other scenarios?