Friends, Romans, Countrymen, it has has come to my attention; that I have succeeded in my 9/22/2012 quest; and killed a fly that deserved to die.  Oh what an annoying fly this was..  Buzzing around, touching me on my nose..  A quick little bugger too..  I tried newspaper, and hair spray, and aftershave..   I missed my mark, I missed again, and I was tormented for hours by this evil spawn of a creature...  But alas, the fly quit flying; landing right next to my hand, and my coffee...  And although I thought  the evil thing was going to fly away at the shadow of my hand crashing down; it would appear that this fly was taken by complete surprise...

Ding dong the fly is dead!

Tell me it wasn't white-headed!

Arrr! But did you try the 'Point'. Yes the 'Point' I tell you. Open the nearest door or window and point to whilst saying "Get out of my house." I find this usually works 7 times out of 10. However, looks a little strange if other people are watching you, especially when they don't know that you're talking to a fly : )

The elastic band is my weapon of choice here.
 
Most of 'em just go about their business or leave via an open window some of them just seem to be programmed to annoy.
 
There's normally a little smear left to be cleaned up and some times some distribution of ancillary fly parts to be taken care of but I never miss if they happen to land somewhere in range.
 
If they are out of range then they don't bother me so the choice is theirs.
 
Annoying me is a capital offence.

The thing is, you have to anticipate where the fly is looking to fly to in the event of a swift attack upon itself.
If you look closely at it's antenna, they will be twitching in the direction of it's planned escape.
Then, the swat is made in that direction 4 1/2 from where you would be aiming.
Simple really.

A piece of clear perspex, or even a clear plastic ruler. They can't see it coming.

A shotgun would have worked equally well. 

does it play on your guitar?

Exactly once a year, usually toward the end of the summer, I'll have the same fly buzzing around my apartment for a least a week. I'll start off completely neutral towards it but by around day 7 I will snap and get the spray from under the sink. It's like, we've had a topping time together old bean, but now you must die. 

 I built a bug laser, a blue ray laser diode with a 9 volt lithium ion battery driver....It doesn't fry the little devils on contact but they are no match for the swatter after one direct hit. Whoo Hoo fly season