Way back, I used to sit houses for people going on vacation - while some only want you to come by and turn lights on, put the mail in, etc, others would have me stay at the house usually to take care of pets which they didn't want to put in a kennel, provide food for me and of course pay me. I have no idea what they pay now, but I was getting $15-20 a day back then for dropping by and $40-$50 a day for staying (plus the food and use of their projection TVs and great stereos). But I was a college student with references, people just don't hire total strangers. Back then I also donated plasma twice a week, helped pay for the pizza and beer. These days you could make $300 - $600 per month in KC donating twice a week - the higher end comes in if you've been vaccinated for Hepatitis B - I found out this info by looking in Google. Donation takes from one to 2 hours. Although I've never done it, certain research medical centers commonly advertise different projects - if you qualify, then they'll pay you good money to take part. Some involve medication, some don't.