I think I have a better answer for this since I have been an investor in the stock markets since a decade and most of my money is either made through investing or trading the financial markets.
Yes you can start investing with as low as 50 GBP or even less. If you are talking about stocks there is no restriction on the amount of shares you can purchase the price of which can be as low as a penny. I stared investing in stocks when I was 18. With the money saved from my pocket money which was not much. But I made investments on a regular period no matter how less I could but I would make regular investments on a long term.
Remember one thing, never trade stock markets always invest in it on a long term. The stock markets will give you the best return on a long term as shown on the graph below and will also save you money on commission the broker charge on every transaction. The brokers to make money for themselves will ask you to trade stocks on short term but stock market were always made to invest on a long term as Warren Buffet rightly says.
And if you want to trade try commodities or forex. Forex brokers will offer you accounts with as low as 25 USD with no commissions. The commission here are all inclusive in spreads.
Is this true? Can the average Joe become involved?
Yes anyone who wants has an interest in the financial markets can get involved. Knowledge is the key not money.
Is it worth investing £50 here and there? Or is that a laughable idea?
50 GBP is a lot. I started with a few Indian Rupees. If people laugh let them laugh. Only morons who don't understand the true concept of financial markets laugh.
There are fees/rules involved, is it worth the effort if you just want to see?
The problem with today's generation of people is that they fear a lot. Unless you crawl you dont walk. Unless you try something you dont learn. The only difference between a successful person and a not successful person is his ability to try, fail/fall, get back on feet, again try untill he succeeds.
I know its not instant money, but I'd like to get a few shares here and there, to follow the news and see how companies do. I hear that BRIC (brasil, russia, india and china) is a good share to invest in
Brazil India the good thing is share prices are relatively low even the commissions. Mostly ROI (return on investment) on a long term would almost be the same.
Can anyone share their experiences? (maybe best for community wiki?)
Always up for sharing. Please ask questions no matter how stupid they are. I love people who ask for when I started I asked and people were generous enough to answer and so would I be.