I got inspired by this Rainmeter P4 HUD: [link] by iron2000 and decided to make a wallpaper based off of the Persona 4 Menu selection screen.
Didn't really know what else to do with the background so I ended up coloring it the same as the textboxes in the game. It should be pretty easy for anyone to re-size to whatever resolution they want, so, have fun!
EDIT: Slightly updated version. My OCDish nature has led me to test my in-game screenshots to try and find the closest compatible transparency values for the edges of the menu bar.. they don't match up perfectly to the game, but it's the best I could do. If someone wants to use the menu bar, alone, and put it on some other background, then I can easily upload the sole menu bar for you with the slight edge transparencies intact.
Also, in case anyone's wondering: So long as you use the provided 1920x1080 file, then the menu bar should be exactly as far from the left of your screen as it is in the game, pixel-wise (when not using widescreen). Obviously, this wallpaper here is widescreen, but I didn't want to rip it from the game like that, as everything would be ugfully stretched.