Introducing a new search feature. You should see a "magnifying glass" icon at the top right. You can search for users by name and also search for circles and tags by keyword. As with all new features, let me know if you find any glitches.
[deleted user] Thanks Mat. At some point it would also be nice if we could search for users by keyword matched to their profile. I'd like to be able to find all the users here who have particular interests, skills, and passions too. Good work!