It kinda depends on why you're doing it like others have said.
when i got my EMT-B, i had been out of school for a year and started a new job in a psych facility and still wasn't sure what i wanted to do for a career.
for me, it was a win-win as it was low cost and little time (one semester) and pretty low stress
but i would be getting a pay raise at work, experience in a new field (or a step towards a career in EMS [ which is NOT the same as emergency medicine mind you...] ) or if it wasn't for me, i would at least have a job option open to me until i found something else or later to supplement my income.
i got about half way through EMT school and decided that it wasn't for me (for various reasons), so i started to look into this adventure of medical school applications after asking an ER nurse who those people following the docs with the COW's were. He said they were scribes, most had their bachelor's, and most would be applying to medical school. i thought to myself "i have a bachelors', and i a while ago thought about medical school" but i never had the confidence to apply.
I got a lot out of EMT school, including coming to realize that i want to become a doctor (not to mention an awesome LOR, and a couple of memorable stories...)
I had in my class, one person who was simply taking emt just to pad her medical school app, and honestly i would not want to run a code with that person because it was obvious she didn't care.
TLDR:
if you think you'll get something out of it, go for it.
if you aren't sure about what you want to do in healthcare, go for it.
if you get in there just to make your app look better, probably other options would serve you better for the time and money
EDIT: just realized this is from 2009, whoops