do you have to join a drinking society to "get in" with the cool kids?

Join one if you want to, but I'm pretty sure the answer to your question is going to be 'No'.

Im talking about drinking Societies, not debating societies...

I know it sounds cheesy, but I've never drunk before, and I'd like to join a drinking society, just because it seems that anyone who's anyone in Cambridge is in a drinking society- as well as all the fit ladies.

Is this true (for instance, many of today's MP's were in drinking societies- would joining one help, for future contacts?)

Many MP's nowadays weren't in drinking societies, they were members of places like the Pitt Club or the Bullingdon Club - with initiation ceremonies where you have to burn £1000 in cash to enter, for example.

The vast majority of students (99%) do not generally do this sort of thing.

In my experience a good 3/4 of people dislike the drinking societies - even people that are otherwise alright can turn into dicks when they're involved in the kind of stuff that drinking societies get up to. There are plenty of people that are popular enough without having to get involved with them, so it's only really worth it if you actually enjoy the sort of stuff they do or are prepared to alienate everyone else to 'get in' with this certain percentage.

At the risk of sounding like a dick (oh the irony), I've never met anyone sociable who assumed I was a dick because I'm in my college's drinking soceity. That said, we're not as rowdy as say, the wyverns/green monsters, and as such, don't have that reputation.

Yeah, I wasn't seeking to make any generalisations about people, just putting across the impression I got in my college (Pembroke), it often feels like the society are tolerated more than welcomed. I freely accept that it's not at all the same for drinking societies, and that I don't know much about drinking societies from other colleges (besides the ones you mention who are barely ever out of the headlines!) And like I say, the guys that come across as dicks when they're with the drinking soc can be perfectly nice the rest of the time.

people that are otherwise alright can turn into dicks when they're involved in the kind of stuff that drinking societies get up to.

Drinking societies are just really weird. They don't exist outside of Oxford and Cambridge, and why would they? Its just a group of people who drink some alcohol and act like dicks - you can do that without needing to refer to yourselves as 'the Myrmidons' or whatever quaint little name you've come up for your 'gang'. There's some interesting psychology in people who need to formalise their friends so - i find it very cute myself. My internal dialogue is 'Aww loud guy with a big belly has found some friends and wants everyone to know about it by dressing up in uniform and shouting more than usual - how sweet'.

Just make normal friends people - jeez.

Drinking societies are just really weird. They don't exist outside of Oxford and Cambridge, and why would they? Its just a group of people who drink some alcohol and act like dicks - you can do that without needing to refer to yourselves as 'the Myrmidons' or whatever quaint little name you've come up for your 'gang'. There's some interesting psychology in people who need to formalise their friends so - i find it very cute myself. My internal dialogue is 'Aww loud guy with a big belly has found some friends and wants everyone to know about it by dressing up in uniform and shouting more than usual - how sweet'.

Just make normal friends people - jeez.

We set a fresher drinking society up, which didn't really have a name or anything official - just a few guys who wanted to set up some swaps to get to know more people (yes, primarily girls) from other colleges.

The main college drinking society seems like fun but also can get a bit weird-seeming sometimes. I think they're all like this in that the people can be a bit unsettling - but it's mainly the atmosphere of a bunch of drunk guys together rather than the people - I know most of the guys in our college's and 90+% are great guys.

But no, OP, the kind of drinking societies you're talking about aren't really the way to become powerful nowadays. Apart from the still-present bias towards people with money, to get to positions of power now you're going to have to do things pretty officially. Get some debating experience, shadow an MP etc.