Sustainable Building Forum

Some of the new houses in my neighbourhood (new ones) list as a sales pitch the geothermal heating.
We have an old house but we considered using this system. We tried to get an estimate from a local contractor, and we have been told that it's worth it if we think adding new additions, like an inground pool.
With the geothermal system we may be able to keep the jacuzzi and the pool heated, as well as having airconditioning in the house in the summer time.

Has anybody used the geothermal system?