I posted this on another forum a year ago. Reposting it now on TE in hopes that it would help others...
Last year (May-June 2010) I spent some time learning ITIL - it started as a decision to educate myself on a subject frequently appearing in job requirements and turned into quite an interesting reading. I'd certainly recommend investing a bit of time into it to anyone who's been in the IT industry for a few years. It definitely helps put things into perspective and see how the daily practice is structured in terms of overall workflow...
It is important to find good material, as some of the books do a terrific job of putting you to sleep

(official ITIL overview publication is one of them). I particularly liked "ITIL Foundations" by James Pengelly (Books24x7.com has an online copy of it).
After contemplating for a bit, I decided to take the exam, and now, having passed it easily, I'm glad I did - afterall, it never hurts to have an extra certificate

Exam name: ITIL v3 Foundation;
Exam length: 1 hour, 40 multiple-choice questions;
Passing grade: 26 points (each correct answer equals to 1 point);
Cost: USD 169 (through ISEB) or 175 (through EXIN) (as of May 31, 2010). A voucher from getcertify4less.com for $120 made it the cheapest exam I've had;
Time investment: ~30 hours of reading spread over 3 weeks seemed like a perfect amount in terms of both gaining the knowledge and preparing for the exam;
Resources:
1. "ITIL Foundations" by James Pengelly (Books24x7.com)
2.
http://wiki.en.it-processmaps.com
3. Official ITIL overview of the subject.
I can't say the exam was particularly challenging as long as you are familiar with the material. At the same time there is no way I'd pass it without studying first, cause while all the concepts made perfect sense, most of terminology was new to me.
As someone who had no previous experience with the theory of IT management, I found ITIL interesting in a sense that it added order and structure to the previously gained empiric knowledge about IT operations.
Best regards,
P.S. I also feel that adding the ITIL cert increased value/visibility of my "career portfolio" - over the past year, I have been repeatedly contacted by recruiters and headhunters, and their alphabet soup of candidate requirements rather often included "ITIL" among other things (this is sysadmin jobs we're talking about).