I just downloaded and installed the latest Ubuntu and it doesn't look like I’m used to. I don’t see any Mercurial developer tools in the Ubuntu Software Center. I got on the official TortoiseHG site and it looks like it can be done, but I’m not entirely sure how. I’ve done some Googling but the results I keep running into are on older versions of Ubuntu. Any ideas on how I can make this happen?
Are you using Unity or Gnome 3? TortoiseHg is a Nautilus extension so will only work with Gnome.
There also seems to be issues being reported with TortoiseHg's compatibility with Gnome3:
Don't know whether these issues have been fixed in the latest version of TortoiseHg. It might be worth trying with the TortoiseHg PPA to get the latest version, as the version that is in the standard Ubuntu repositories tend to lag behind a bit.
There's some info here regarding it working again in 12.10.