Hey Joshua, firstly brilliant that you are starting investing so young! To be honest I would go with a mining site and do Bitcoin mining. I think P2P lending with Bitcoins is very high risk due to the fact the whole thing is pretty much unregulated.

Have a look at http://www.ukcbitcoinblog.com because there are a few mining sites there (top left corner). I just think it would be a safer investment for you, and at $25 a week (about 0.025 ish) I think you'll quickly build a large mining pool that will be quite profitable.

To add, I use a number of mining pools to spread the risk. I've got a section on the site as well under Getting started that talks about Bitcoin Mining.

Basically as far as I can see it there are pretty much 3 ways to make money with Bitcoins.

• Mining
• Holding Bitcoins until they go up in value and selling them
• Running a Business

all of which, even though you are only 15, you are free to do because this currency ENABLES people to be free!

Good job buddy!