Day trip wise, Mt. Saint Louis Moonstone is the other local bump/hill that's worth spending any time on. But it's almost the same as Blue, but without the good restuarants and bars at the base of the hill.
If i could make a suggestion.
If you're traveling to come to Ontario, head east and go to Quebec, Mt. Saint Anne or Mt. Tremblant, you won't be disappointed.
Mt. Tremblant looks good. Is it far from Barrie? I'll be travelling with the wife, so I figure we could hit two local hills, like Blue and maybe Moonstone or Horseshoe, and then take a daytrip and try something bigger in the east. How's Calabogie?