[XeTeX] What is the best way to simulate small caps?

[Andy Black]

Hello,

When a font family does not have a true small caps font, what is the 
best way to simulate small caps? 

Would something like this be OK or is there a better way?
    \fontspec[Scale=0.65]{Times New Roman}{\MakeUppercase{prog}}

I'm using XeLaTeX with the fontspec package.

Thanks!

--Andy