Based on what I ve seen around the internet in print and especially in Apple s and eBay s writing it seems they should be capitalized as they appear even when at the beginning of a sentence eBay is a great auction site is correct EBay is a great auction site is incorrect Ebay is a great auction site is also incorrect EBAY is a great auction site is super duper incorrect eBay example About eBay eBay is The World s Online Marketplace enabling trade on a local national and international basis Apple example iMac comes with iLife 06 a suite of easy to use applications that make the spectacular part of your everyday life Both accessed 6 June 2006 As for typing in ALLCAPS well that is bad style anyway I don t think any way would be more correct in an already incorrect situation like that so I ll say nothing