Designing Kitchens and Bathrooms - Installing Countertop Without Cabinets?

Hello all. I'm a recent first time home buyer, and would like to cut out a window in the wall between my kitchen and my great room to open it up. I would also like to put a small strip of countertop on the windowsill, to create a sort of serving bar/sill between. Problem is, I can't find any info on how to anchor the counter top without cabinets.
Any suggestions?

Thanks!

Josh

First suggestion is to deternine if your ceiling will fall down when you make the cut out for the new "window". By window do you mean a pass through - essentially an opening without glass? If the wall you are opening up is a load bearing wall you will have to make sure that the opening is framed correctly with a header adequately sized to support the load.
What size countertop do you plan on installing. Also you have to decide on material. The installation of a wooden counter is quite different than installing granite or marble.

As Wayne indicated, the first step is to make sure you adequately support whatever is above when you cut out the opening.

Now, the method of support/attachment for the countertop itself will vary a little depending on the material. However, most countertops have an edge that extends down 3/4" - 1" below the bottom of the actual top. This gives you the ability to attach a 3/4" thick piece of plywood directly to the plate (make sure it's perfectly level in both diections) which overhangs on both sides of the wall to fit the "recessed area" on the bottom of the actual countertop. The plywood will then be concealed by the edge of the countertop.

If your top is a wood or laminate surface, you can use screws up thru the plywood to secure the top. If it's a solid surface material then you simply use silicon sealant.

Counter can be supported by countertop supports anchored to studs. The standard white steel supports are not very attractive, but they are very strong and can support up to 100 lbs. Wood corbels come in a variety of sizes and decorative styles. A visit to a kitchen cabinet dealer will help you explore your options.