Lots to do in Cape Town for the non-kiter:
Sport:
World class cycling (get up early for cool temps and avoid the wind) including the famous "Cape Argus" route up Chapman's peak. Good cycle lanes and many many groups who ride if you want to cycle with others.
Good tennis courts, good gyms; local Virgin Active has a 20m salt water pool with lanes for serious swimmers.
Multiple world class courses with green fees 1/3 of what you pay at home.
Food:
Great food culture with fantastic eating options all the way up from budget/bistro prices to fine dining. Expect to pay 40-50% less than you would in Europe and wine is priced at about 20% of what you would expect to pay in Europe.
Steak lover? Epic grass fed steak dinners for 200 rand. You will be a food coma afterward.
Coffee lover? Amazing pride and care taken in turning out great coffee. Visit "Truth Coffee" on Buitenkrant for example: coffee warehouse at the back (you can walk around admiring the coffee sacks from around the world, dodging forklift trucks... health & safety hasn't quite caught up here ...) in the middle of the store watch it being roasted; at the front enjoy a perfect espresso/milky coffee in the steampunk themed diner.
Wine farms:
Speaking of wine the wine estates here are gorgeous places to visit; of course you can do tastings, but many also have fantastic restaurants onsite as well.
Big city:
Being a big city, Cape Town has all kinds of cool districts to visit with funky furniture, art and retro shops. You can easily spend a day or more investigating the cool shops (permanent and pop-up) in the Woodstock and Observatory districts.
Clubs:
The epic Shimmy Beach club with DJs local and flying in from around the world; speakeasy type gin bars that you enter through the back of an apparently closed chococolate shop; the overflowing bars of Long Street. Great night life!
History:
The Dutch Fort; District 6 museum/Robben Island to learn about apartheid; the painted Victorian houses of the Bo'kap district
Nature:
Climb Table Mountain (set off early to avoid the heat). Watch out for a "dassie" (large guinea pig like animal) scrambling through the rocks.
The world-class Kirstenbosch gardens. The nature reserve at De Hoop (you can stay overnight). A drive through the Overberg farming district with a night in the whale-watching town of Hermanus. A trip up the West Coast to the fishing port of Paternoster and enjoy a local kreef (crayfish) braai (bbq) by the beach.
Visit the African Penguin colony at Simon's Town (if you visit at low tide you can swim near the penguins in the natural rock pools).
For the kids:
Amazing aquarium downtown at the V&A. If they are old enough, the cable park at Blue Rock or Hillcrest/Durbanville. The "Bird Life" avian theme park. Ratanga junction theme park. The beach!
For the driver:
Stressed out by the traffic at home? Sure Cape Town has a rush hour (queues heading in 06.45-09.00 and coming back out 15.00-17.00) but for the tourist setting off at 10.00 or heading anywhere but into town Cape Town has fabulous driving roads: top down (pretty much insect free in Summer), 26C temps (but wear a hat against the sun). I love driving here (and I hate it at home).
And those are just the first few things that came into my mind ...
James / BA
Cape Town Kite Club
http://www.capetownkiteclub.com