Pico diGoliardi , Jul 23, 2006; 01:20 p.m.
You cannot increase a raster image's size without loosing something, unless perhaps it's a subject with no luminance changes, flat colors, all within the scope of a GIF file (for the web). It is a matter of physics, of fact.
The best you can do is to interpolate in 10% increments with very modest unsharp mask applied at certain stages. In your case the increase is not severe so try that. I forget if PS7 has actions, but if it does, use them and be happy.
Just don't waste any money on Fractal Magic and similar theftware.