Updating drug guide

How often do you replace your personal drug guide?

Mine was published in 2009, but I have been looking some of the newer versions that some of the first years have and wondering how much the information might have changed.
I still have a 1998 Tarascon (for old time's sake if nothing else). I usually look anything up on Micromedex, they update it and it's free.

If you have a PDA or ipod or smart phone get Epocrates. Updated daily, free and has every drug on the market, awsome!

I am starting a job in LTC and I am wondering if it is common to use an iPod in these facilities? I have such useful information on mine.

My first one was a 1991 edition, then I got a 2000 book, then a 2005 book. Less likely to get a new one now that I can look drugs up on the internet. I recently bought a Galaxy Tab that I take to work with me. It makes it very easy to look up drugs while at work.