Night Club Photography

Hi, I have been trying to figure out some tecniques for shots in a dark place with lots of extra light around, like in a night club.

I found some pics of what effect i would want to achieve taken from propaganda night club have a look
http://slyraccoon.dot5​hosting.com/files/pics​/prop1.jpg

http://slyraccoon.dot5​hosting.com/files/pics​/prop2.jpg

http://slyraccoon.dot5​hosting.com/files/pics​/prop3.jpg

I can see that the first 2 use a wide angle/fisheye lense 16mm or even less and i presume an external flash with a defuser set to low setting and prolonged exposure to capture the background light... but i have only a standard Canon Eos D1000 and i need to set it to the closes settings, i tried putting the flash to minimal and set it to bulb to play around with the exposure time
it iether over exposes or hits a straight up ugly flash like so:

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The first two looks like they used a fast lens with a large aperture.

Have a read in this thread. Will keep you busy for a fortnight

OK, I got the Idea of it now , thanks a lot for your help those threads are great.. let me share my plans, and you tell me if it is a good way to go about it.
I don't have enough cash for a fast lens, but I'm planing to throw all my budget on getting an external flash with a diffuser and wireless triggers. I suppose that alone will be enough to get some decent photos going.
I have a Kit lens (18-55mm | f3.5 - f5.6) and i don't understand how the aperture works i mean i know what it is and how to use it but WHY can i at times use 3.5 and other times i cant set it below 5.6?

For the most time ill be using these settings:
(Manual)
Exposure: +- 1/4
Aperture: 3.5 or 5.6
ISO: 1600
Set the flash on low, and let the angling and bouncing the light do its magic...

Here is a question: I know about light, but i have no clue about flashes, could suggest what flash i should get and why?

p.s. for others who might be interested in this thread (here is a great tutorial on Club/Bar Photography)

That's common on the cheaper variable focal length lenses. f/3.5 at 18mm, & f/5.6 at 55mm.

Thanks for that, I thought it had to do with the light conditions; hiding underneath blankets, saying 'comon!!! how much darker do you want it to be?!!