Q: what is the best external drive to use with time machine?

I back up every day, I also have 2 back up drives, which you should also have, if your data is imporant to you.

A Time Machine back up, and a clone (which is bootable)

I use a OWC Elite,and a IOmega.

Use Time Machine on OWC:

ttp://eshop.macsales.com/?utm_source=google&utm_medium=cpc&utm_campaign=adwords& gclid=COCM8O3uuLsCFSUOOgodVBEAOwuuLsCFSUOOgodVBEAOw

IOMEGA:

http://www.amazon.com/s/?ie=UTF8&keywords=iomega+portable+hard+drives&tag=googhy dr-20&index=electronics&hvadid=3927029335&hvpos=1t2&hvexid=&hvnetw=g&hvrand=2132 262008473015365&hvpone=&hvptwo=&hvqmt=b&hvdev=c&ref=pd_sl_2k8gsvyzks_b

These are but a few that are available for affordable prices, I have had very good performance from both, there is going to be many other opinions, and all are valid, I just sat stay away from WD as they have been problematic.

Do a web search you will find tons of drives, at different prices, and capacities, choose one or better still two and back uo to 3 different systems.

I use Time Machine and Carbon Copy Cloner:

http://www.bombich.com/

Also check into SuperDuper:

http://download.cnet.com/SuperDuper/3000-2242_4-46651.html

Hope this helps

Keep in mind that Carbonite is an off-site backup. If someone breaks into your home and steals your computer, they could take your external drives too. If there was a fire or flood in your home, everything would be at risk.