ClamCase iPad Keyboard Case and Logitech iPad Keyboard are pretty cool,but too expensive. I tried to look for an alternative,and then I found the review about Sharksucker Keyboard from JSXL Technology.It is really an awesome alternative with high quality but much lower price.
http://www.jsxltech.com/blogs/review/6757690-sharksucker-keyboard-review-from-jsxl-technology
http://www.jsxltech.com/blogs/review/6757690-sharksucker-keyboard-review-from-jsxl-technology