Pen will tell you if you are spelling wrong

Interesting project where the pen will tell you if you are spelling something wrong (vibrate).  I like the idea, not so much the pricetag of $150 each.  Its a kickstarter project, so maybe it will come down in price over time.

http://techtree.com.feedsportal.com/c/33242/f/556609/s/2eaaf4ec/l/0L0Stechtree0N0Ccontent0Cnews0C41750Clernstift0Esmart0Epen0Erefine0Ewriting0Eskills0Bhtml/story01.htm