Thank-you for your question.
There are a number of online databases of company and official logo's:
Best Brands Of The World (over 100,000 logos)
"brandsoftheworld.com site is one of the most visited web sites
intended for search, browse and exchange of the World's famous
As for july, 2005 we have:
* more than 100.000 logotypes in vector formats;
* more than 1 million page views and up to 40.000 visitors daily;
* several terrabites of traffic monthly;
* more than 10.000 users, who visit site at least several times per week;
* more than 200 active contributors (logotype authors, digitizers),
who upload up to 100 new brands every day;
* ... and a lots of people around the world, who use the project
for their work, who interested in this project, who want to keep it
AllTheLogos.com (90,000+ logos)
"AllTheLogos.com is an online database of logotypes and logo design.
This includes more than 90,000 companies and organizations brands
logos, team sports logos, countries flags and insignia as well as
signs, general usage logos and more. We hope to provide inspiration
for designers as well as become a visual guide to the pop culture
behind brands. You can either view the logos alphabetically by
clicking on the category links or do a search for a specific brand.
The logos are also available in vector EPS format."
Logotypes (4993 logos)
If you require any further assistance on this subject please do not
hesitate to ask for clarification.