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).