Currency/stockmarket trading

Have any of you dabbled in these areas? I have very limited experience. It's something I want to try to get into but I can't really afford it just now. All I've done in the past is invested £300 in barclays when uk banks were in a lot of trouble and sold for (iirc) £2,600 six months later. I wanted to invest £1,000 that we had saved but my girlfriend kind of got cold feet when she was in the process she bought £300 just in case we lost it. Oh well. Next time I'll do it myself.

Bought £300 in centrica but had to sell before we made any money at all because I was 50/50 with a friend and he needed his money back to pay bills.

A relative who goes to turkey on holiday every year has just changed up £1,000 into Turkish lira and compared to the normal exchange rate he got an extra £12O worth of lira.

Just a couple of examples, I'm sure some of you have much more experience than me. It's something I want to get more involved in and maybe soon I'll be able to use my scrap money purely as a way of raising money to invest.

Messing with stocks can be very rewording an if you do not have alot of money but would like to "play" around then I would look into penny stocks...they are fast moving stocks an you do not have to invest alot of money...but you have to look into any company to make sure its not a scam...penny stocks can be bad things...just use google alot on a company that you may or may not know.