Getting a border collie, how to keep them sharp?

I have decided to get a young border collie in 2-3 months from a rescue, and I will be taking them to puppy school, but after that I don't know which route to take. I know they are smart dogs, so I want to give them a weekly or bi-weekly activity, either agility, herding clinics, obedience, or other physically and mentally challenging activities. I know they can excel in all of them, but I haven't decided which one. Suggestions? Preferences? Any recommended groups specifically in the Phoenix area?Thanks to all who reply!

They cant be Sharp let the be their Self's

dude border collies are awesome. My gf's dad has two and i use to have 1. He keeps them happy cause he has all these little tricks and games that they have made up and the dogs caught on. Its the best part of my day to play tag with a dog lol

Agility seems to be very popular amongst Border collie owners in our area. I love to watch sheep dog trials, but logistically, it could be hard to get access to sheep to practice on regularly. Obedience is an extension of puppy school and you should just continue that training at home.

I would do agility. Check out DOCNA, Dogs on Course in North America. They are in your area, I'm not sure how close. I know Jim Mills lives in AZ, just not positive how close to Phoenix. I'm sure he could help you locate someone close to you.

Agility! And you are VERY lucky to be asking this right now, as the USDAA nationals are held in Scottsdale Nov 11. Although the main focus is agility, there are other dogsports going on as well, including some you can try out and get lesson in during the 5 day Cynosports Games. Here is some info on it:http://www.usdaa.com/article.cfm?newsid=1308Phoenix also has several agility groups in the area, some of which may also have other dogsports available:http://googility.com/map/?startaddress=Phoenix+AZ&sa=Map+Search