Laser Cutting/Engraving

At work we use several company's for laser cutting. I'm not sure brass can be lasered, i am sure copper plate can't be lasered.
So probably water jet cutting would be a better option, we have one company we occasionally use for water jet cutting. Waterjet is a bit more expensive then laser.
You would have to convert the bitmap to a DXF, which is the common file format for this stuff.

Thanks guys I've now found a few companies that can water-cut the design out of brass.

Now... anyone know how I can 'smooth-up' a bitmap file and then convert it to a dxf? I have a conversion tool but the original bitmap is blocky and I'd like it nicer.

www.Inkscape.org has a pretty good bitmap tracer built in.
Or if it's a simple design you can trace it manually with autocad or other cad programs.
www.qcad.org and www.solid-edge.com/free2d/ are some free cad programs

To expand on what Stu said:

I used to do a lot of desktop publishing work. I would frequently receive, given to me as source art for a publication, a logo or a line-art design in a very low resolution (or very small) format, sometimes even just a dirty photocopy. It was my job to take that and enlarge it for proper publication. Usually, scanning the supplied art was the first step needed.

There are pieces of software that will auto-trace the outlines of a bitmap and turn that into a vector file (such as DXF, EPS, or WMF). These work. However, the resulting outlines will be somewhat blobby and imperfect. For example, in places where you would expect the lines to be parallel, they might not be. In places where you would expect a straight line, you might get a slightly curved one, or vice versa. If there is any "noise" to the image, that will become separate elements in the vector file.

In many cases, what I instead did, was what Stu suggested:
1. Make sure your bitmap is monochrome (black and white only), as opposed to something that contains shades of gray or color. Do a conversion in your photo-editing application if necessary.
2. Open a new document in Corel Draw (Or AI or whateva).
3. Import the monochrome bitmap into the document.
4. Resize the bitmap to fill the page.
5. Change the bitmap's line color to light gray, so that your logo is now gray-on-white instead of black-on-white.
6. Put the bitmap on a non-editable layer, and put that layer in the back.
7. Make a new editable layer in front.
8. Use the bezier editing tools to create the logo using vectors. Use the gray logo in the background as your guide. Create your vectors in the color of black so that you can see them atop the gray bitmap outline in the background.
9. Do not use the line thickness features to create your logo. If you need a thick line, make an outline of that line with a fill of black.

When you are done, make sure all objects in your design have no outline at all, only a solid fill color of black. The logo must look right in this way, or the DXF cutting software won't work on it as you expect it to. Delete the gray bitmap and its layer. Export to DXF. Make sure the DXF looks right when you re-import it into a fresh document (preferably in a completely different program, like Microsoft Word or something). Send to cutter.

All the previous suggestions are what I would do, trace manually or tidy up an automatic tracing.

However try all avenues of getting a vector logo, or at least a higher quality bitmap first, it will save a lot of hassle. I have a CAD vinyl cutter and when cutting "official" logos unofficially (mainly for movie prop vehicles) I find that PDF documents on the organisation's website is a good source of high quality versions.