We have updated private messages with some upgrades to make it more useful.
1.) When you go to your private messages (profile -> private messages), you can now just type in the name of a user to message and it will autocomplete the rest to help you find them. You can also just enter the entire name. Users must have more than 1,000 points to appear in the list.
2.) When messaging a specific user (hit the reply icon) you can now see a scrollable list of all your conversations with them.
3.) You will see a list of recent contacts to make it easier to select conversations.