Take the seaplane from the River Clyde close to the Exhibition and Conference Centre for a day trip to Oban. The scenery is pretty stunning (weather permitting, of course!). Trips also available from Loch Lomond.

Visit the Glengoyne Distillery - beautiful countryside setting and not a bad drop of Whisky produced there too!

"Must visits" in Glasgow are (at the very least):

Kelvingrove Art Galleries and Museum (located in the West end of Glasgow)
The Burrell Collection of art (South side)

Or base yourself at the foot of Loch Lomond for a few days -either at Balloch or just a bit up the road that runs North-West up the South side of Loch Lomond (although the majority of Hotels located here might be considered to be "up market" i.e. - expensive!)

If the weather is good then you'll have a great time! If the weather is bad -then enjoy the Scotch!