Check out Jason Becker's "Perpetual Burn" and his stuff with Cacophony. LOTS of good arpeggio ideas, they might spark some more for you, and change your mindset on how arpeggios can be used.
Throw in some scale runs mixed in with your arpeggios, a la Bach (since that's who all the neoclassical guys seem to model themselves after), and you can get some cool results.
Edit: Forgot to add: Serge, the idea of tapping up an octave is pretty cool, I'll have to try that.