Remember Apple's $1.99 charge to update current laptops to 802.11n? Well, according to Lynn Turner, former chief accountant of the Securities and Exchange Commission, "[generally accepted accounting principles] doesn't require you to charge squat."
She adds, "You charge whatever you want. GAAP doesn't even remotely address whether or not you charge for a significant functionality change. GAAP establishes what the proper accounting is, based on what you did or didn't charge for it."
Despite this, Apple still maintains that if they gave away the 802.11n patch for free, their auditors would have required a revenue restatement, which may in turn cause...*yawn* sorry, we just fell asleep writing this sentence. Suffice it to say, Apple still thinks charging you two bones to activate 802.11n is a good idea, even if top tier accountants say they're not obligated to.
Apple Gets a Bruise by Blaming A $1.99 Fee on Accounting Rules [WSJ - Thanks Kelly]