Dog's got it right. Illustrator AI files are vector format files, infinitely scalable and sharp as a tack at any scale. Unfortunately, vector formats are not supported by Web browsers, unless you count the limited support for SVG and the plugin-provided support for Flash.
Your issue is probably coming from the conversion to one of the Web-supported raster formats, jpg, gif, or png, followed by scaling. When you scale a raster image upward, pixelation is introduced, producing the fuzziness you are observing. Impossible to say more without seeing the image itself.
[EDIT] BTW, if you're using Illy CS4 to produce that logotype (and, I suspect, earlier versions as well), you can select File|Save for Web and Devices. This will bring up a fully-featured dialog that will permit you to choose many options, including Web-compatible file types, color palette minimization, etc. Before invoking the dialog, you can also losslessly scale the logo to the desired size while in vector format, yielding the sharpest possible converted Web-compatible image.
If you are not producing the logotype yourself, talk to the creative who is doing that part of the work and ask him to provide you with a Web-compatible image with the file type, transparency, color depth, size, etc. that you need for your design. It's cake to do in Illy, and he should have no problem accommodating your needs.
paladyn |