Hi Jimmy,
My bet is you are using a CMS or Shopping Cart on your site. The software is generating these seemingly random URLs, and the Google crawler is seeing them.
Crawlers don't move through your site the way people do. If you take your home page and right-click, then choose View Page Source, you will find many URLs. The crawler will then follow each and every URL throughout your site. The URLs you are seeing could be generated on any given page.
To track the issue, use the SEOmoz crawler on your site, then analyze the results. When you find these types of URLs, take note of the page they are located on.
Alternatively, you can contact your CMS or shopping cart's software developer and inquire about the URLs. If these URLs show a folder path before the random characters, that information can help track down which pages or software is generating these pages.