I can't help with medical trials in your area but I have taken part in one where I live. The main problem I found was that they tend not to cater very well for people who work. The one I attended didn't offer weekend visits and they tend to vary on the number of nights and days you have to stay. Basically I got �500 for 3 nights / 3 days with 2 visits for checkups prior to the stay and one check up afterwards. I spoke to some people who use these trials almost like a job as you can take part in one every 3 months or so. The hardest part I found was having to stay lying down for so long whilst they checked your heart. My back and neck really killed me the first couple of days.