Payday is Friday - Looking for "Investment" Ideas

I get paid this Friday. I'm now looking for ideas on what to invest on/in.

I talked to my friend who actually is interested in finances and majored in international finance, and he thinks that $100 is not enough to start investing in the stock market. Looks like I'll have to start with some transaction investments. I know a few people who made quite a bit of money from buying electronics and reselling them on ebay. Maybe I'll try that.

Plus Interest - The Backstory

I am 23 years old living in the Bay Area. I graduated in 2009 with a degree in Health Services Administration. Up until now, I still have not been able to find a job within my chosen field and am now working as a martial arts instructor.

Although the job is fun, it barely pays the bills (or student loans for that matter) and I came up with this idea. Using $100, I want to see how much I can make, be it through interest (high yield), dividends, or physical transactions. I will not just put it into a savings account and wait for it to gather interest. I wish to utilize physical transactions (buy low-sell high via ebay for example), invest in the stock market, and things of that sort.

I have no prior experience or knowledge with any financial subjects, other than having a savings and checking account, so here's the twist, if I ever get any readers on this blog, they will be the ones to choose how I invest my money. If they want me to buy magic the gathering cards to resell, I will do that. If they want me to buy a refurbished laptop, I will do that. I will not, however, invest in something that will obviously fail, like pork bellies, nor will I do anything illegal.

This blog is just to document my successes and failures (most likely), and if I should lose my $100, I will save up and try again.

Now to save that $100...