This by no means qualifies as a splash, but the Detroit Lions did make a move right at the start of the 2014 league year by re-signing wide receiver Kevin Ogletree, according to Pro Football Talk. The deal is for one year, and chances are it's a minimum type of contract.
Ogletree joined the Lions during the 2013 season. He ended up playing in 12 games for them, and he finished the year with 13 catches for 199 yards and 1 touchdown. He was far from overly productive, but he showed some flashes here or there as a potential contributor going forward.
Considering Ogletree's deal likely didn't cost the Lions much, it's not a bad idea to bring him back as extra depth. At worst, he ends up being a camp body and is let go before the start of the season. At best, perhaps he develops into a consistent contributor at wide receiver or is at least there in case injuries happen higher up on the depth chart.
In short, this was a low-risk move that gives the Lions extra depth at wide receiver going forward.
UPDATE: Here are the details on Ogletree's contract:
Kevin Ogletree one-year deal with Lions worth $795,000, including $100,000 guaranteed, including $65,000 bonus— Aaron Wilson (@RavensInsider) March 11, 2014