Trilled r sound.

[Kaltxì Palulukan!]

This has probably been covered before, but I just happened to be helping someone and found these. If you have not found a good sample yet, here is some rr sounds, and some vowel sounds as well.

rd (or r-r-r)
http://www.freesound.org/tagsViewSingle.php?id=13634

rd (or r-r-r) and an "l" sound--I was just after the "rr"
http://www.dadap.net/korun/sounds/wav/rl.wav

This one is a bit more obscure, but you can really pick out the hard "R-D" sounds in the gibberish. (I have no idea what language it is)
http://tolklang.quettar.org/pronlo/sounds/quenya-rhotics.wav

And finally this one, which is about how to speak Spanish "rr's", but has a lot of good examples:
http://spanish.about.com/library/media/audio/rr.mp3

or
(a e i)
http://www.dadap.net/korun/sounds/wav/aei.wav

or
(o u and something I can't figure out)
http://www.dadap.net/korun/sounds/wav/ouy.wav