Type “make cash online” into Google and you’ll probably be inundated with all manner of shonky get rich quick schemes. But even in these credit crunchy days, there are legitimate ways to earn a few extra pounds using the internet.

It’s unlikely that any of these ideas will make you a life-changing amount of money, but they’re a good way to generate some readies with relatively little effort.

1. Put some adverts on your blog or website.
Even if you only have a modest level of traffic, you could make some pocket money by signing up to a program like Google AdSense. These advertising systems automatically analyse your website and display relevant advertising.

You earn money every time a visitor clicks an advert on your site. It might pay for your hosting – or if you get lots of visitors, it could make you significantly more.

2. Run an online shop in your spare time.
Actually, if you do this one right, it could make you quite a bit of cash. A great way to start trading online is to do it in your spare time, and to sell something that you’re knowledgeable or passionate about.

If it takes off … well, it could become a full time job. And as it doesn’t take much effort to get started (just decide what to sell, then set up an online shop with an ecommerce package), you don’t have much to lose.

3. Get cashback when you buy online.
One of the web’s best kept secrets is that you can often claim cashback on items you buy. All you have to do is visit a cashback site, then follow a link from there to the shop you’re buying from. The cashback site gets paid commission for your purchase, which it passes on to you.

I’m a big fan of Quidco, but there are other cashback sites too, including Top Cashback and Cashback Kings. I saved £40 on a laptop from Dell last year and nearly £100 on a holiday, so it’s definitely worth signing up to one of these sites, then using them whenever you buy something online.
Beginners’ guide to cashback sites >

4. Sell your skills.
If you’re a mean amateur photographer, you could sign up to a site like iStockPhoto or ShutterStock and sell your shots. They could get used on websites all over the world, and you could make a few quid too.

If you don’t mind performing sometimes menial tasks online, you could sign up to tasks with Amazon’s Mechanical Turk service. Or offer your professional services on sites like Elance, Guru, peopleperhour.com and oDesk.

5. Get paid for giving your opinion.
If you’re the sort who always opts to fill in surveys online when given the chance, you might as well sign up to be a panelist on a site like YouGov.

Once you’ve registered, you’ll be able to earn money (typically 50p or £1 a time) by filling in surveys. The surveys you’re offered depending on whether you fit the profile each survey is targeted at.

6. Think up a bonkers idea.
Do you remember Alex Tew? He came up with the Million Dollar Homepage idea in 2005, and generated $1m in revenue by selling pixels on it off at a $1 a time. It caught the imagination of the press, and became a bit of an internet hit.

I wonder how much of the $1m was swallowed up in income tax and bandwidth charges, but you’ve got to give the guy credit for making a success of an idea which seems pretty rubbish at first glance. Think you know what the next million dollar homepage will be? Do it quickly, before someone else does!

What are your tips for making money online? Leave a comment and let us know…