How can I find or generate thousands of company names for testing and demo purposes? (Address, phone number, and related information would be nice too.)

I've got a system I'm building which includes business contact information. Pretty common no doubt.

My test/demo database currently has randomly generated individual's names loaded (thanks to a handy IRS spreadsheet I found). This has worked great for internal testing and review purposes, but it looks really odd when shown to prospective customers.

I've tried various online public information sources (e.g. EDGAR, and county based property records searches), but these all require me to manually stitch together the results in blocks of 50 names or so at a time. I could do this, but was really hoping for a search service or data store out there that had this type of information readily searchable and retrievable in very large batches.