Just made another Module in the last few hours, to fill a gap which I couldnt cover.
MOSFET Output Module 
This board has 8 MOSFETS which do High Side Switching, which are selectable in 2 groups of 4 outputs to select 5V switching or External Voltage switching. The 5V switching I have limited to 200mA shared between the outputs, however will be good for PWM'ing or switching high impedence inputs, such as Stepper Motor Drivers etc. The External Voltage switching is so you can provide it an external voltage, such as 24VDC, and the outputs will then output that voltage (minus the voltage drop), so you can therefore PWM 24V etc.
The MOSFETS I am using are IRLZ44N (http://www.irf.com/product-info/datasheets/data/irlz44npbf.pdf), which are Logic level.
I will probably limit the switching current to 1A or 2A, as I dont want to have to provide massive heatsinks, even though these things are capable of switching massive currents.
Still have checks to do to make sure I have done it right, but it could be a very handy module to have.
Today I went around to my mates place, who has a few projects for me, and we figured out the requirements of each project. Each of his projects will use 6 or 7 of the modules, so will be a good test of how they perform. 2 of the projects required this new module, hence me putting effort in this evening to make it.
Comments welcome, here is a picture.
Information was gained from this old post, so I will mention it - Thanks to those involved.
http://www.arduino.cc/cgi-bin/yabb2/YaBB.pl?num=1230677423
James