BTW, I bought something similar to this keyboard
http://www.cartft.com/catalog/il/478 for a different project some time ago (a CE tablet). While it is no ergonomic marvel, I still type on it faster than the silly on-screen default keyboard. I am going to try it with the edge now too to see how it does - some velcro tape should take care of attachment pretty well I am thinking. The price on the above link is kind of high - I was able to find it on Ebay for ~15 USD.
Basically, my hangup with the on-screen keyboard is the silly iphone-like look and feel, which is totally irrelevant for our large-screen device. I think the numerical/special characters should be easily accessible - the default keyboard takes a second to switch between the alpha and the numeric view making text entry for me an utter pain (esp. passwords and punctuation). I looked at BetterKeyboard, which meets my requirements very well, but they have it locked up good in the blasted Android Marketplace. I have started looking an the Android SDK and one of the first "hello world" apps is a keyboard - I will give it a whirl too to see if I can build a less brain-dead on-screen keyboard and make it available on the alternate marketplaces with available source code.
I am kind of up in arms about this topic since I made myself spend an entire weekend using the edge as a netbook replacement/reader. The experience was pretty good but was totally ruined by the sucktacular default Android keyboard. I even tried the Slide keyboard and while it is interesting, it didn't do it for me.