Yep!
Extensis Pxl Smartscale Plugin for Photoshop. Have it.
The results are very good but it still gives a blurry output (dependent on upscale ratio), the only solution is to sharpen the edges but then artifacts start to appear.
Actually, Photoshop does a pretty good job itself. The trick is not to try to make a huge 200% jump in scale but rather resample in 10% increments.
