Hey All,
Well after lurking, reading and getting a huge amount of information from this forum, I thought I better post my first effort at building a MAME cocktail cabinet.
Anyway, a good mate of mine built a cocktail cabinet a few years back and I thought that would be a pretty cool project to give a go, so after biting the bullet I decided to give it a crack this year - and with a lot of people on this forum, the project is taking a loooong time as life has a habit of getting in the way!
Firstly, here is what I wanted to get out of my arcade machine:
1. A simple design - nothing fancy, just a decent looking cocktail arcade machine (not even sure if I will put any artwork/decals on it).
2. I wanted to include an extra control panel so that you could play 2 player games side by side (eg: 1941, Street Fighter, etc). I read all about the pro's and con's, but decided to go ahead with it.
3. I wanted to use a LCD monitor (again I read all the pro's and con's on this as well) as I will be using it as a normal computer from time to time and also plan to install a TV Tuner card in the computer that powers MAME, so it can function as a multipurpose device.
After deciding exactly what I wanted I spend a good few weeks doing a lot of design work. It felt like I was spending so much time designing it that I would never get around to starting any of the actual 'real work'! I look back now and am glad I spent a lot of time designing!
Right now I have done all of the woodworking (except for the top) and have built and painted the cabinet. I have also attached two control panels, but not the 2 player one yet. Last night I spent a few hours doing a lot of the wiring (I ended up using Cat5 cabling for the wiring as I would be able to make it 'look' neater once finished). It feels like I have learnt a heap of stuff from woodworking to building a computer from scratch and a lot about cabling and wiring, so it has been an awesome project to get stuck into.
Hopefully I will have it finished sometime in the next month or two, so I'll keep this updated with progress and photos. In the meantime here are some snaps of the build so far.
(I would appreciate any comment to hear what you think could be improved/changed/etc so if I ever do it again I could make it better).

Cocktail cabinet finally put together and painted with a undercoat/primer (no top yet) - it took a couple of months just to get to this point
The holes are for (from top left to top right): Power switch for whole cabinet, Power button for computer, switch for switching between control panels, Fan, 3 x admin buttons (Pause, Menu, Tab). The two holes at the bottom are for the power cord and an RCA jack to connect external speakers

Control panels all done and painted with an undercoat/primer. The CP are on a hinge so I can access the wiring easily.

Finally painted the cabinet and put one of the CP's on. The two holes on the near side are for the internal speakers and the hole on the same side as the CP is for another fan.

I made a mistake with the 2 player CP - the joystick mounting was to big for where I had drilled the joystick hole. I tried a couple of fixes, but no good, so I had to redo the CP top and rearrange the wholes for the joysticks and also the 'credit' button.

The Player 1 CP with the wiring done. I am going to tidy up all the wiring before I finish, but this was more a 'test' to make sure it was all going to work. Same with the inside of the cabinet - I promise it will be a lot neater when finished!
I'll post more pics and updates when I get around to it.
Thanks again to all the posters from this site - I have got so much information and help from reading people's post! THANKS!