Disclaimer: For mechanical engineers, I personally think that getting a PE often is a good move.
However since this is Slashdot, I would argue that for computer engineers this is not always true, or at least the easiest thing to do in the United States.
While completing college, I took and passed the Engineering-In-Training state exam for Electrical Engineering. I then worked for several years with various employers, some of which had PE's above or adjacent to me in the hierarchy; others of which did not.
The electrical engineering exam for PEs seems to be bending-over backwards to reverse the small percentage of licensed EE's relative to other disciplines. When I looked into this a year ago it was possible to take a purely computer-oriented exam without a lot of the power, electromagnetics, and other topics. The state certifying board where I currently live seemed more than willing to consider justification statements proving that work I did while not under the supervision of a PE could be credited as work experience.
At the time I also was a member the local NSPE/state society, attending meetings with lots of other PEs, and being flooded with offers of legal and civil engineer training courses.
But I never could get PE certification before my EIT expired. The catch was I could not find enough PEs that would be willing to sign of on me as a personal reference, largely because most felt uncomfortable with their knowledge about what I had done.
And since there are so many exclusions to when you can use the term "Engineer" without a PE in most states, I ran out of PEs to ask.
For Mechanical Engineers getting your PE often can be a good thing. But for Electrical Engineers and Computer Engineers especially it can be a chicken & egg problem.