Explore Lake Burley Griffin - on or off the water. You can:
Hire a paddle boat, canoe or kayak and mess around on Lake Burley Griffin. Hire is available from:
Lake Burley Griffin Boat Hire, Acton Jetty Acton. ph +61 2 6249-6861 (Note: The lake may be closed when algae blooms are significant)
Row'n'Ride, Canberrra Avenue, Fyshwick. ph 0410 547 838,
Alternatively, take a scenic cruise on the lake with Lake Burley Griffin Cruises. Phone 0419 418 846.
If you're up for some exercise, you can walk, cycle or skate around Lake Burley Griffin (approx. 25km). Hire is available from:
Capital Bicycle Hire , which rents high quality mountain bikes and runs tours around Canberra's extensive bicycle path network and off-road trail system. Phone 0412 547 387.
Mr Spokes Bike Hire,  Barrine Drive, Acton. ph +61 2 6257-1188 Offers a wide range of bikes and has two seated pedal cars (the ones with steering wheels) which can be a lot of fun and great when taking smaller children. There is also a small shop selling high quality gelato and beverages. Plenty of parking near by.
Ride Canberra's Mountain Bike Trails: Canberra offers a large number of Mountain Biking locations around Canberra, many of which are considered some of the best in Australia. See Canberra Off Road Cyclists (CORC) for locations. Canberra is also home to the largest 24 hour Mountain Bike Race in the world (Scott 24hr), held in early October each year.
Explore Tidbinbilla Nature Reserve is about a 40 minute drive south of Canberra via Tuggeranong Parkway and Tharwa Drive. You can take Ranger-guided walks or have fun with the hands on displays such as the interactive computer program on Tidbinbilla's bird species and look at the live animal displays. The gift shop sells an interesting range of clothes, toys, books, cards and souvenirs. Coffee and light refreshments are also available.
Go tobogganing in Corin Forest, Tourist Drive 5, ? +61 2 6235-7333. Weekends, ACT school & public holidays, 10AM - 4PM. This alpine recreation facility features a bobsled ride in summer, and snowplay and tobogganing in winter. It is high enough to receive natural snowfalls. Check the website or call before heading up that the road is open, and that there is snow. Free entry, rides from $7, all day pass $35.  edit
See the stars and planets at Mount Stromlo Observatory, Cotter road, Weston Creek. ph +61 2 6125-0230. Mount Stromlo is Australia's premier astronomical observatory. Badly damaged in 2003 bushfires, the partially rebuilt observatory reopened in October 2004. They run a Saturday night star gazing event for the public, call +61 2 6125-0232. The site's damaged buildings and equipment remain and may be fascinating for tourists.
Go wine tasting in the Wineries around Canberra (most are outside of the ACT but all very close to Canberra). They are described as cool climate wines and some are very well known and regarded. Try Jeir Creek, Gallagher, Clonakilla and Lark Hill, just to name a few. There are '33 wineries within 35 minutes of Canberra'. Visit the Canberra Wineries website for more information.
Take a scenic drive into the southern ACT - recommended by locals:
Head south to Tharwa, and then take the road to Adaminaby. The road is very good for all of what I describe, any car can go on it, but further south than what I describe requires a 4WD. Take the road out of Tharwa, and remain on the road for about 10km. Take the signed road to Honey Suckle Creek. Very important historical site, this is where the signals from the Apollo 11 space landing were received, and then beamed around the world. Also a nice drive, and a very good camp ground.
On the same road, not far off the Adaminaby Road is a walking (Fire ranger) trail to the top of Mount Tennant. About a 5 hour round hike, but worth every step. Go back onto the Adaminaby road, and head south. Another site of a space centre on the right down the road, worth a look, but not as interesting
Remaining on the road for another ten kilometers, entering the Namadgi National park, and two hundred meters after a single lane bridge is a signed turn off to Yankee's Hat. This is a four km drive, any car can take it, and look for Kangaroos. Hundreds either side of the road. The walk to Yankee's hat will take you to see aboriginal art.
Road to Adaminaby. If you have a robust vehicle, take the road south. The country is magnificent. It takes about an hour from Yankee's hat.
Visit the National Zoo and Aquarium, 999 Lady Denman Drive, Weston Creek ACT 2611. (Take Parkes way and follow directions), ? (02) 62878400, . This privately owned zoo and aquarium offers the standard service plus special tours that allow interaction with the animals. The range of tours offers opportunities to interact with animals (feed or touch) including tigers, lions, cheetahs, giraffes, bears, dingos, elands and snakes. The tours are quite special and certainly worth it if you love animals. Make sure that you turn up at the 'Check in time' instead of the start time as the two are different.