Few days ago I made myself usb host adapter and it's working great with my thrusmaster t-wireless 3in1 gamepad with fpsece.
If you wan't to build adapter yourself you can either try to buy 24 pin connector that ipaq uses or hack one of those 2 adapters that came with your ipaq (like I did). I used one with usb cable attached to it, and later regreted that I didn't use the other one as that cable is really getting in the way when using joypad. All you needfrom spare parts is usb extender cable from which you cut off male plug and solder 4 wires to 24 pin ipaq connector.
Here is pinout of ipaq connector:
http://forum.brighthand.com/showpost.php?p=1654053&postcount=7
You will need pins 5, 6, 7 and 8.
You can find usb pinout here:
http://en.wikipedia.org/wiki/Universal_Serial_Bus
After soldering cable I had to cut the piece of plastic from 24 pin connector so I can close it and glue it back.
I tested it with usb stick, usb full keyboard, usb numeric keyboard (which can also be good replacement for gamepad), usb mouse, usb (wired) gamepad and usb wireless gamepad. It's all working flawlessly. I read somewhere that mouse pointer doesn't work. I was testing it only in Windows Mobile 6.5 and it IS working. You can use it same way as your desktop mouse and keyboard.
To use usb gamepad you will need this driver:
http://www.fpsece.net/forum2/viewtopic.php?f=13&t=423
Alternatively, you can buy usb host adapter from e-bay, but they are too expensive for so simple cable.

Hi
I follow your indications and finally build a usb host cable for my ipaq 216, how i do for show the mouse pointer on the screen when i connect a usb mouse?, this works but the mouse pointer is not show...
Please help me with a driver or program for that, i try with mpointer but it not work in this device

Thanks and forgive my english!

I would like to appreciate your help. I got my own USB host adapter because of your help. You have shared it with some article type materials that are too good and more informative. I use the most your wikipedia material for doing this.

@ivancho75: I think that original 6.0 ROM doesn't support it by default. With the previous version of WM 6.5 ROM I had, mouse pointer worked without any programs installed. I just checked again and with the WM 6.5 ROM I'm currently using (I think it's one of Sony66's latest roms found here it doesn't. I googled a bit and found a solution. Google for zeno usb host drivers v6.0a.rar install it on your ipaq and you'll get a mouse pointer.

@jacklinjones: I'm glad I could help