Need something to practice?

Couple Mudvayne tunes. Especially off their first record L.D. 50. They have a great bassist who plays finger style, finger taps, slaps and does double and triple stops.

Those are basically hitting 2 notes at a time or 3 for triple stops.
For those, he makes a pretend pick and uses his nail to pick the stops...

Look into his technique.
Buy one of their live DVDs for a nice drooling experience and to realize how bad you are. (I watch them daily... hehe)

You can also check out Dream Theater. Great technical prog rock with skills you are looking for. John Myung has a video on his tehnique but it is like $50 and is 90% modes and scales.

I have no clue about your skill level but you could do what I do...
It involves modes and scales so if you aren't too in touch with them then work on that too while you are on vacation. Get those scales mastered!
I used to take a mode and draw it out on a piece of paper (I made tab paper on the computer and printed it out) From there I took a couple of the lower notes on the E and A string and combined them with notes past the 12th fret in the same key on the D and G strings. I then made up finger tapping things and moved my right hand around to hit more and more notes in the same key. Then do the same with the left hand. Eventually you work on finger tapping, keeping tempo and percussion with the left hand, maneuvering your fingers differently on the right hand as well as mastering the fretboard and scales...

 

Bass Grimore is a great book for modes and scales BTW...