I mostly use fotolia and bigstockphoto right now. You can find my pics at: http://us.fotolia.com/p/200589069 and http://www.bigstockphoto.com/search.php?q[...haq&q[ao]=1.
I found this great program called Cushy Stock for managing my uploads. The main thing is it automates keywords and uploading to the microstock photo sites. check it out: http://www.cushystock.com .
Here's the software author's summary:
"How to manage your digital images and vector files at the photo stocks? What photography workflow software do you need? What tool helps you to upload your images from a digital camera to photostock? Do you need describing, keywording, cataloging, uploading, tracking software? Congratulations, you've found it! Let me introduce the Cushy Stock tool! "