Hey guys... I saw that tmacman001 already did a great tab for this and I 
thought I'd add in the little riff that goes on during the intro. This is my 
first tab :) It sounds right when you play it along with the song so here goes:

CAPO 2
Tabs are relative to capo

Intro (Guitar 2)
     E             Aadd9       E             Aadd9
e|---4-------------------------4------------------|
B|------------7/5--7------------------------------|
G|---------------------------(4)--------7/5--7----|
D|------------------------------------------------|
A|------------------------------------------------|
E|------------------------------------------------|

The rest of the song is at 
http://www.ultimate-guitar.com/tabs/r/relient_k/youll_always_be_my_best_friend_tab.htm