Ok, so here's the thing: introducing Gerhard Richter and doing abstract paintings about color mixing using scrapers is easy. It fits into the elementary curriculum, and uses a contemporary artist as an example. Also, Wolf Kahn. Landscapes with alternative colors. Almost Fauve-ish. I use sculptors like Mark di Suvero and Richard Serra in a "monumental sculptures" lesson at 5th grade. I like to add Janet Fish for still lifes and Anselm Kiefer for using texture under paintings.
But what about Michele Oka Doner? Check her art out at: http://www.micheleokadoner.com/home.html. Her sculptures are very intriguing, but how do you use her in elementary school?
How do you use Tara Donovan? http://www.acegallery.net/artistmenu.php?Artist=8#
Also, German conceptual artist Mario Reis. http://www.fassbendergallery.com/Reis/index.html It would be fun to try to replicate his work in a nearby stream in a unit combining science and ecology. maybe I'll think about that one.

contemporary art in the elementary art classroom

I have been teaching for some time, always including art history and artists in my lesson plans. I have not had Internet access most of my career, and have only used the visuals that come with textbook adoption, posters from museums,and calendars.
Then recently, I attended a Graduate course in contemporary (artists are still living) art history and it blew me away! There were so many good contemporary artists that I was on fire to share them with my students. What I discovered was that 1) there are not many resources out there for using contemporary art in elementary art classrooms, and 2) much of the art is so conceptual that it is hard to use on an elementary level. (Well, and 3) lot of nudity and inappropriate content!)
One thing that did work for me is the number of artists using recycled materials (like Tara Donovan) and objects from nature (think Andy Goldsworthy).
I'd like to move my art classes into the 21st century, but here are the "Givens": I still only have 40-45 minutes once-a-week with each class, I teach in an urban school, so not a lot of $ for supplies, and, of course, I still have to correlate with core academics (math, reading, science), no computer access--for students--in the art class, although I can sign up to use the "flex lab" and take a class there once in a while if I plan ahead.