Springfield XD Magazine Sleeves?

Anyone know of a company making magazine sleeves for full-size Springfield XD magazines? These magazines work in the sub-compact models, but extend from the bottom of the frame a decent amount. I thought I heard that some one was going to be making sleeves that would slide over the full size magazines so that you'd have a conituous grip surface if you used them in a sub-compact, but I haven't been able to find anything so far. Anyone know of something like this that's out there, or at least planned for production?