What is this Vietnamese noodle called?

If it's eaten without the broth, then it's call bun (pronounced like "bon").

If it's eaten with the broth, then it's pho.

Judging from your description, I think you had bun, which is just noodle, pork, shredded lettuce, cucumbers and carrots and served with fish sauce.

Here is a photo guide to identifying Vietnamese noodles: there are many types:
http://images.google.com/imgres?imgurl=http://lh5.google.com/whiteonricecouple/R33h-aIWlKI/AAAAAAAACKo/vZs1ND__1FA/s800/Noodles%2520105.JPG&imgrefurl=http://whiteonricecouple.com/blog/noodles-asian-vietnamese/&usg=__HFXQjZ_JbJSZrpgxGF7b2r4YNLM=&h=600&w=800&sz=82&hl=en&start=12&um=1&tbnid=0oCbbDPMBXN-UM:&tbnh=107&tbnw=143&prev=/images%3Fq%3Dtypes%2Bof%2Bvietnamese%2Bnoodle%26um%3D1%26hl%3Den%26newwindow%3D1%26safe%3Doff%26rls%3Dcom.microsoft:*:IE-SearchBox%26rlz%3D1I7DKUS

i think you're talking about pho. it's served as a bowl of white rice noodles in clear beef broth, with thin cuts of beef (steak, fatty flank, lean flank, brisket). variations featuring tendon, tripe, meatballs, chicken leg, chicken breast, or other chicken organs (heart, liver, tongue,[citation needed] etc.) are also available. there are also various vegetarian varieties of pho

Pho

...it's a 30cent pack of oodles of noodles that they charge $8.95 for!!!!??