Twitter is a great tool for indie artists to grow their business. Here's a few good posts I found recently on how you can use this little bird to bring flocks of customers to your store.

http://www.theartistscenter.com/wp-content/uploads/2009/02/2.png
http://www.handmadeology.biz/home/archives/214

Personally, I've set up Twitterfeed and it sends everyone of my blog posts and new etsy items out to my followers. I also use twitter to promote giveaways by sending out tweets every so often during the day while I am working. It can also be a good tool to meet other artisans. I follow a lot of other etsy sellers and got a radio interview on Blockhead Radio for my bag team because I saw someone in my network tweeting them looking for a guest.

Get to know the bird and you won't be sorry.