Before i go on this only works on servers with these types of voting rewards
1. Get firefox and install this addon https://addons.mozilla.org/en-US/firefox/addon/966
2. Goto the voting page of your server with firefox
3. Open tamper data by going to to tools->tamper data
4. Click start tamper and go vote
5. Once you have voted tamper data will ask you if you want to tamper the page and click tamper.
6. Change the "reward" ID to any other item you want eg. 12947 (alex's ring of audacity) and click ok
7. Go ingame and check your mail box
also there is this addon that gets custom item id's ItemID v1.7 - Mod Development - World of Warcraft Mods, Addons, and More!
just type /itemid (link the item here)
Here is a list of servers with this type of reward system:
Vote Rewards
WoW Caelum - Where gaming meets heaven
Omegawow Voting
OMGWoW Server
http://draculaswow.ath.cx/vote.php
http://wowenforcers.org/news.php
(if you find anymore servers that it works on pls post it and i will add it to the list)