there is a search function (methinks)

All my new Plurk friends are people who've replied to my friends' plurks. You could also look at the interesting plurkers page

You could also use this third-party tool to find people from a particular geographical region.

And BTW **Hi bunnywabbit!!**

There's no direct equivalent of Twitter's "at" replies. The usual thing is to reply to a plurk. Others pitch in and you have a conversation.

You can write a plurk that can be seen only by one person or a defined "clique". But you need to add them as friends first.