The Detroit Lions are pretty set at the wide receiver position. Calvin Johnson is potentially the best in the NFL at what he does and was recently rewarded with an appearance on the Madden NFL 13 cover. The team also has young prospect Titus Young, and they're hoping that he makes the jump this season and breaks out. On top of that, the team recently signed Maurice Stovall.
Stovall was with the Lions last season and played special teams, but the team isn't done bringing in wide receivers. According to the official website, the Lions worked out free agent wide receiver Jarett Dillard on Monday and have signed him to a one-year contract.
Dillard played with the Jacksonville Jaguars a season ago and caught 29 passes for 292 yards and a touchdown. The team released him in May, and some consider him to have some decent potential to make it on a roster and see the field as a wide receiver (and not just on special teams). He does have some injury history though, missing the entire 2010 season with a foot injury that really set him back with the Jaguars.
Detroit will need to make room on their 90-man roster for Dillard and there's no word yet on how they're doing that.