Hey PEOM,
I side with those who said "ammo & range time"... may not seem as cool, but it is probably the best use in terms of preparation for defense.
The grip reduction to get the gun fitting your hand better is also a really good option.
The .22 Conversion kits aren't something that I am a big an of.
The laser is a great enhancement to the pocket gun, but being able to shoot your 23 better is a much better defensive option.
-RJP