Where can I find a client to download?
From the Download page: http://www.livejournal.com/download/ , select the appropriate link for your platform/operating system.
Because the clients are updated frequently by the individual developers, you will then need to access the journal for the specific client you want. There, check the most recent post in the journal for a current download link for that client.
Obviously, it can be reworded to something other than my standard canned answer :P, but I think it comes up often enough. /download/ does mention in the summaries of the clients that one should view the journal to download the client, but I'm not so sure it's read by most people.