I agree with some of the comments that blog post received, the 20% personal time for ideas is fine as long as the ideas/work you come up with is a potential money maker for the employer. If you are going to work on your startup idea during that time :-), then I'm not sure how many people would be willing to let you do that. I only have 3 things I need from an employer: 1. good co-workers 2.challenging work. 3. Salary worth the time+effort.

#2 is interesting. I don't know what might happen if you ask to see your potential coworkers' code during an interview, but it could be a great way to avoid landing on some train-wreck of a project.