We all know it takes a small army to plan a wedding. Chances are you or someone you know could use some help in the wedding planning department. Well, TaskRabbit actually wants to help. We’re giving one lucky couple a handy-dandy TaskRabbit for a week* to help plan, run errands, and finalize arrangements for their big day. Need someone to pick up linens? Finalize invites? Fight your battles with the caterer? Well, there is a TaskRabbit for that! On Friday, August 12th (8:30 pm ET) one lucky tweeter will win a TaskRabbit for a week* to help with wedding arrangements. To become eligible, simply follow @TaskRabbit and retweet the message below: TaskRabbit is giving one lucky couple a TaskRabbit for a week to help with wedding planning & I just entered to win! RT to enter. #weddingrabbit Here are the rules: 1. How to enter: Entrants must have a Twitter account and then become a follower of @TaskRabbit, located at http://www.Twitter.com/TaskRabbit. Both new followers and existing followers of TaskRabbit are eligible for this contest. If you do …