There are two work at home companies that I worked while I was in college (I do not recommend them).
Teletech and LiveOPS.
LiveOPS you're a independent contractor. You have to pay for your own background test and a dedicated phone line, computer/internet. After the training, you take calls for late night infomercials/commercials and then try to sell cruise/magazine packages to those customers. You only get paid while you are talking to customers, not while you are sitting around waiting for a call. I ended up spending more money getting started on this, then what I ended up making overall.
Teletech you're an employee for a call center who works at home. It's part-time $8 an hour, no raises and no benefits with a set schedule. Depending on what company you are working for (Bestbuy, Western Union, ect) you do customer service, sales or tech support. I ended up dealing with extremely pissed off people and had to calm them down. As soon as someone hangs up you are routed another call. You have use their interface to look up customer information during a call, use email to customers, fill out reports about each call. After the first week 2/3 of everyone I started with in training had quit or were fired. New hires were added to the call in pool about every week. I ended up making about $200-400 a month because of the hours. They had lots of tech issues where the entire call center network went down and it booted you off the system and they don't pay you while you wait around for them to fix that, it happened several times a week.