Guidedog allows you to use your webcam to autoguide any ASCOM supported telescope mount. In addition, mounts with a CCD Guide Port can be guided through a parallel port based relay box.

Features

• Dedicated, standalone, easy-to-use autoguider software
• Supports the SC-1 long-exposure webcam to allow guiding on faint stars
• Uses ASCOM for scope control to support many different telescopes/mounts
• Support for parallel port based relay boxes to connect to the CCD Guide Port of most mounts
• Sub-pixel guiding on a star centroid
• Audible alarm if lock on the guide star is lost
• Runs under Windows 98, 2000, ME, and XP without having to install additional port access drivers

For my setup with the Losmandy G11, I used my parallel port on my PC. To the parallel port I had to purchase a GPINT-PT adapter from Shoestring Astronomy (www.shoestringastronomy.com). Also picked up a 25 ft RJ-12 cable  from Shoe String to go between GPINT-PT adapter and Autoguider port on the Gemini Control Box.
I used my Meade LPI or ToUcam to acquire the guide star. Open GuideDog. Screen will open as shown below.Of course my imaging scope is slewed to what I want to image. And a star is centered in my guidescope by adjusting the rings.




In the tool bar, set up your camera,guiding,telescope and options. Very good instructions can be downloaded from GuideDog website.Once evrything is finished in setup, click on the Preview button. An image is now displayed on screen from your guiding camera. You may have to adjust the exposure slide bar to see image. Next you click on the focus button, and focus image. I use a Hartmann Mask here to do the focusing. You can also center your image  while focusing. Once your happy with the focus, click on the lock button and right click with your mouse arrow on the guide star. A two ringed recitile will appear on screen with your guide star in the center. The Lock button will turn from red to green. Now click on the Guide button. This button will also turn from red to green. Below this button you will notice the dx and dy numbers.I had to play around with the aggressivness slider and exposure rate. All of this is explain in the directions. 
I was autoguiding the first night out. GuideDog kept my guidestar centered for over 5 hrs. Could have gone longer but clouds rolled in on me. I know if I can set this program up anybody can do it. 
On the GuideDog website is a Discussion forum which is VERY helpful. Steve Barkes, the programer for GuideDog is there to answer any and all questions.
The software does not currently work with the Meade DSI, but Steve is working on the codes. 
I am very happy with the performance with GuideDogs ability to track and keep my guide star centered. I know this program will greatly increase the quality of my astrophotos.
The best part is this program is FREE. But donations can be send to Steve to help offset all his time to improve a great program and add more codes for new cameras.