...or at least our minifigures can be. A store called BrickCommand.net has entered the scene selling minifig scale Klingon Bat'leths. A few of these have been popping up on Flickr with positive reviews.
Brick Command is also selling ninja stars which are held in the figure's hand by 'ball handles'. Although their selection isn't deep, these appear to be solid items. There are also a few brick kits for sale as well.
As always 'buyer beware', but you can check them out at BrickCommand.net.
Thanks to Entropy for making me aware of this.