There's a public thread open at Club Charybdis. It's on the corner of Knockturn and Diagon, second floor of the building. The first floor is a real estate witch. The club is only open past 9 pm (which is why we don't see it in the books) and tonight is their tenth anniversary, so half-priced drinks!
Feel free to drop your character in, and make up any number of unsavory types you meet along the way. It's probably attracting a bit of a different crowd than it did a year ago ... make up any details? Just reply with them to this post so we can keep it all together!