The San Francisco 49ers are a team that enjoys mixing in some rather crazy formations and personnel groupings. We saw it last year when they motioned Leonard Davis out to the wide receiver position in one game. We got another instance of it against the Cardinals when reserve offensive lineman Daniel Kilgore lined up at wide receiver. James put together a GIF of the play, and you can see Kilgore lineup at the top of the screen.
That's certainly some route-running!
The play itself is interesting, as Vernon Davis ran a corner route that picked up 28 yards. When the cornerback realizes Kilgore is the guy lined up opposite him, he switches off with the linebacker before the play starts. The corner runs deep with Vernon, and Vernon makes a pretty spectacular over-the-shoulder catch, on a perfect pass from Kap.
It is entirely possible we don't see Kilgore line up wide again the rest of the season, but it's now on the film for teams to consider.