How many houses can you manage with a full time job?

[Mike Krieg]

I'd love to hear from people who have jobs on this. How many houses, or units do you feel you can handle? Some of this depends on how flexible your job is of course. I'd love to know how close people feel they can get to critical mass (replacing your income) while holding your existing job. And additionally, what are some of your tricks to automating things to take out lost time, hassles etc in landlording?