OK, due to popular demand, here's my tried and true method of hacking analog arcade controls to a Dual Strike interface.  This method has worked for both my Star Wars yoke and Terminator 2 guns, and others have used the same process for steering wheels, analog pedals, and more.  It should work with any analog controls using 5k pots.

First, you need a MS Dual Strike.  I got mine at Comp USA for $20.  The first thing to "strike" me about the DS was that, although it looks like another Playstation-style gamepad, the right half of it is actually an analog handle that rotates up/down/left/right very much like aiming a gun.  It happens that the output of the pots in the DS is 5k ohms, just like an analog arcade controller!  The DS pots are 3/4-turn pots with a resistance of about 20k ohms.  The hardware of the DS actually restricts the handle so it turns about 45 degrees left&right or up&down. This gives a little less than 1/4 turn, giving a resistance of around 5k!  This makes the DS a perfect candidate for arcade hacking, since it only expects an input of 5k to begin with.
 
Even better, the DS comes with software to configure it as either a joystick or a mouse, so it can be used with any Mame game with support for either one.  Joystick support seems to work best in most games.  And all the buttons can be configured for any keystroke or macro that you want.
 
So far, I have hacked Dual Strikes into two Terminator 2 guns, as well as a genuine Star Wars yoke.  All three devices worked perfectly upon completion, with minimal tweaking in Mame.

 
 LETS GET ON WITH THE HACK ALREADY!!!

 This is a description of how I hacked the Dual Strike into my Star Wars yoke (actually from a Turbo Sub prototype).  The first thing to do is open up the DS.  Take out all the screws (there's about 8 of them, don't miss the one behind the label) and pull the thing apart.  Watch the inside of the aiming handle--it's full of lubricating goo...    At this point, locate the main printed circuit board (inside the larger half of the gamepad.)  The main PCB looks like this:

You can just cut the wire connections between the main PCB and the button PCBs, but be sure to leave a couple inches of wire attached to the main PCB, for easy soldering later.

You can unplug it from the PCB to make your work easier, but don't cut it.  If the white sleeve comes off with the plug, slide it back down on the pins and super-glue it to the PCB so it won't happen again!
 
Here's the hard part:  You need to de-solder the pot from the center of the main PCB.  A copper de-soldering braid makes this job easier.  Place the end of the braid over the pot connections on the back side of the PCB, and apply your soldering iron over the braid and allow it to soak up the solder for a few seconds.  Repeat until you've removed most of the solder from the 3 pot connections.  Now, just heat one connection for a few seconds at a time, slowly prying the pot off the other side of the PCB.  Alternate between heating the 3 connections until the pot finally squeaks free of the board.

Now you'll need to identify the connecting wires on your analog arcade control.  On the Star Wars yoke, there are 4 sets of red, black, and white wires--2 for the triggers on the right and left handles, and 2 for the x and y-axis pots.  If you have a set of torx security wrenches (http://www.therealbobroberts.com/ has a nice snap-in set for cheap) you can open the center plate on the yoke, and tug on each set of wires so you know which is which.
 

Then wire the connections as shown above.  You'll need to solder the wires for the Y-axis pot to the PCB (where the old pot used to be) but the rest you can just twist together with the existing PCB wires, solder together and insulate the connections with a drop of hot-glue or some heat shrink tubing.  NOTE: If you're doing a gun setup, swap the red and black wire connections on the PCB for the Y-axis pot.  This is because the gun uses a flipped Y-orientation (up=up, down=down) opposite from the yoke's orientation (up=down, down=up).
 
Note, the connection labeled Ground above should connect to the green ground wire bolted to the yoke's chassis.  Only the connection labeled Common above should be used to make the connection with the commons (black wires) from the microswitches.
 
Also, the white microswitch wires are for the triggers, while the red wires connect to the thumb buttons on each handle.
 
Now, re-connect the USB plug to the PCB, use the screw holes to attach the PCB to a convenient spot inside your control panel, install the DS software and drivers, and you're ready to go!
 
The buttons are actually connected where the D-pad on the DS used to be.  In your DS config, change your keystrokes for UP, DOWN, LEFT and RIGHT to be CTRL, ALT, Space and Shift, in whatever order you prefer.  Set up Mame for sensitivity, axis swapping etc, and get ready to experience authentic arcade action as it was meant to be!