Not sure of what you mean by 'overlay', but look into a tile with bullnose product by Benissimo.

Its a product that lays over your existing countertop.
See granitetransformations.com. Its a thinner granite,
but no demolition.

Their web site is geared towards franchisees. It's not granite, but engineered stone-and-polymer. No pricing on the site. Cool concept though.

A friend of mine was quoted $35 per sq ft.

There have been several posts on this over at the Kitchens forum. As I recall, the selection was limited, and the final end cost was really not much less than a regular slab, sometimes even more expensive. Granite slab prices have REALLY come down in recent years. Where we are, you can get pre-fab slab granite installed for as little $25/SF. Prices of $45-55/SF are very common for full-custom.

Try a search over there for the full story.

Could be useful, though, for those who want to avoid the cost of demolition.