If you have some trouble with the timing in doing tabs but you want to be sure to remember the exact fretted note you played, here's how I do keep a notebook of my riffs ideas:
-once I have a nice riff (or something I seem to care to remember later) I play it in front of my tiny Nikon Coolpix, making a short clip with the riff at full speed and if it's useful, the riff at roughly half speed (or slower anyway).
-I keep some tab lines preprinted on a normal sheet of paper (i made mine using Photoshop, it's just six lines in five, six rows) and by pen or pencil I write down the tabbed riff, careless of timing and or accents, etc...
-When I want to refresh my memory I just play the .mov little movie on my computer (I store all my riffs in a Folder and I do backups on a DVD, every once in a while) and if I have trouble seeing which fret I was playing the note at, I take out the paper and go reading it.
That's it, it works for me. And sometimes worked even for my band (it's still difficult to teach ideas to other people when it's something that was uheard before, it takes a little effort from the people you are teaching the riff to).
It requires a small digital camera or a phone that does record little videoclips (but seriously, which device doesn't do it these days?) but it's a very straightforward way to keep ideas.
I wish I had the time and mindspace to learn proper music (in general, not only guitar riffs) notation, though.
GP4 is so much better in nearly every respect.
