The best solution, of course, is to develop this "sound recognition skill". While the amount of work it takes get there is significant, the benefits far exceed the mere ability to transcribe what is in your head. Most people think that the ability is magic, so that whe you develop this ability, people will think you are some kind of musical genius. It is similar to how the computer illiterate respond to programmers.
I use pen and paper. Anything else is an (understanably neccesary) shortcut. I feel for the trees, but I havent found an iPad app that allows you to simply write on a representation of staff paper yet.