I'm a to-be uni student and have the option to go to either Sydney or Canberra. Admittedly, Canberra is the best place to be for the degree I want to do. Currently, however, I live in a relatively small, homophobe-stricken town in regional NSW, and refuse to go from a place that has no gay scene to another when it would cost me just as much to live in Sydney.

So, my question:

How prevalent is the gay scene in Canberra? I mean, it's a city of sorts, so it's bound to have something - and it's obviously not going to be as big as Sydney. But... it DOES have a scene, right?

Good question. I've been asked to join someone for an Easter trip there. I've only ever passed through and seen the tourist attractions.
I believe there is at least one gay bar.

it really only has cube plus or minus a few that open then close

I looked at Cube's web site. It says you have to be a member or cannot gain entry unless accompanied by a member. Sounds a bit fussy and not encouraging for interstaters only in town for a night or two.

Your'e right Canberra's gay scene is relatively small especially in comparison to Sydney.
Cube isn't just membership only - anyone can get in (I don't recommend wearing a football jersey though). Saturday night is moslty referred to as str8 night - last time I was there there were heaps of str8 chicks doing the tiny dress with their clackers hanging out thing (seriously I seen way too much female reproductive organs for my liking but hey...). It's OK as far as gay clubs go, nothing particularly special, the music is mostly mainstream (like really matt , gaga three times in the one set) & some of the people not out to prove themselves are friendly. It's mostly OK.
There is also Bar 32 which is obviously more a small bar but is gay owned (I believe) & gay friendly. It's a little less mainstream music wise. It's OK for a bar. There was another bar thingy in the suburb of Phillip but it closed recently.
I find though that alot of the gays in Canberra aren't terribly worried about gay clubs etc. They just go where the music is good or house parties etc.
U get shit from time to time from wankers but mostly Canberra is reasonably chilled.

Cubes fine... make friends via grindr etc etc, there are good people out there, you just might not meet them every weekend