Here is a blog that has some great history on how a few companies were named. Very interesting

A quick sample before you follow the link.

Apple- for the favourite fruit of co-founder Steve Jobs and/or for the time he worked at an apple orchard. He was three months late in filing a name for the business, and he threatened to call his company Apple Computer if his colleagues didn’t suggest a better name by 5 p.m. Apple’s Macintosh is named after a popular variety of apple sold in the US. Apple also wanted to distance itself from the cold, unapproachable, complicated imagery created by the other computer companies at the time had names like IBM, NEC, DEC, ADPAC, Cincom, Dylakor, Input, Integral Systems, SAP, PSDI, Syncsort and Tesseract. The new company sought to reverse the entrenched view of computers in order to get people to use them at home. They looked for a name that was unlike the names of traditional computer companies, a name that also supported a brand positioning strategy that was to be perceived as simple, warm, human, approachable and different. Note: Apple had to get approval from the Beatle’s Apple Corps to use the name ‘Apple’ and paid a one-time royalty of $100,000 to McIntosh Laboratory, Inc., a maker of high-end audio equipment, to use the derivative name ‘Macintosh’, known now as just ‘Mac’.

Red Hat- Company founder Marc Ewing was given the Cornell lacrosse team cap (with red and white stripes) while at college by his grandfather. People would turn to him to solve their problems, and he was referred to as ‘that guy in the red hat’. He lost the cap and had to search for it desperately. The manual of the beta version of Red Hat Linux had an appeal to readers to return his Red Hat if found by anyone.