Programmers have always liked CamelCase, but now marketers are making it trendy.
CamelCase (also known as medial capitals, intercaps, humpbacking, CapWords, and BiCapitalials, among other names) is the practice that has now become trendy of promoting a letter in the middle of a word to uppercase.
Most often the capital letter in the middle seems to result from squishing two words together that would normally be separated by a space (e.g., MySpace), but occasionally the capital just seems to pop up at a convenient syllable (e.g., OutKast).
Although the phenomenon can be traced back to at least the 1950s, it gained steam among computer programmers (probably because spaces are often discouraged or disallowed in programming, so a convenient way to highlight multiple words in a file name or variable is to capitalize the first letter of each squished-together word). More recently, marketers decided it was a trendy way to make a company name stand out.
If a formal company name uses CamelCase (e.g., YouTube, PayPal, TiVo), use that form in your writing; but other than honoring official names, leave the camel at the zoo--don't go around calling a plain old help desk a HelpDesk. It's UnNecessary!
Get more tips like this in The Grammar Devotional: