Spuds,

If you have a Husky, check out http://dogscooter.com/

My Samoyed has been pulling since she was 18 months old (the age at which it is said their joints are sufficiently mature for such activity). She pulls me on a Blauwerk "Willy." We also do bikejoring, more and more as she's now a senior dog and having me on the bike takes most of the pulling stress off her.

She can still top out around 20 mph. Scooter weather is fast approaching (must be under 55 degrees for me to hook her up).

I get the tow lines and harnesses ("Urban Trails Harness") at Alpine Outfitters:

http://www.alpineoutfitters.net/secure/scripts/prodList.asp?idCategory=33