But what about a more unusual way to make money? Flu Camp is paying volunteers thousands of pounds for taking part in medical trials. Let's take a closer look at how it works.
There are all sorts of simple ways to boost your bank balance, from taking part in a boot sale to taking up direct selling in your spare time.
What is Flu Camp?
is a medical trial facility in Whitechapel in London.
As the name suggests, volunteers are given the flu. Some will just be infected, some may be given an external vaccine before the test begins, while others will be given anti-viral drugs after infection.
The trials involve staying at the facility for between eight and 14 days, where you can be monitored. You get your own room, with an en-suite bathroom, and there's plenty of entertainment on hand in the form of games consoles, TV, computers and the like.
You'll then need to visit the camp daily for a little while after the trial so that the staff can monitor how you are recovering.
Is it safe?
Safety is an important question. After all, back in 2006 a trial testing a drug which tackled leukaemia, arthritis and multiple sclerosis hit the headlines, after a number of volunteers suffered significant side effects including vomiting, organ failure and head swelling.
I spoke with Dr Rob Lambkin-Williams, who was keen to point out that with Flu Camp the infections and drugs given to the volunteers have all been tested before. As a result it's highly unlikely that you'll experience such extreme side effects.
The staff at Flu Camp will also monitor you for a while after the trial to make sure you are recovering appropriately. If you take longer than expected to get over the infection, you may be asked to come in a little more frequently.
Who can take part?
Volunteers need to be aged between 18-45 and in good physical health. You won't be able to take part if you have any underlying condition which may be negatively affected by the trial, such as asthma.
To be accepted onto a trial you first need to complete the online form. You'll then take part in a telephone screening, which will go over your basic medical history.
After that, there's a panel screening appointment and a full medical to get through.
Once you've cleared that, it's on with the trial! According to Dr Lambkin-Williams, around 20% of people who initially express interest make it through to the trial itself.
Exactly how much you get paid for taking part depends on the trial involved and how long you need to stay at the camp. However, you can earn between £2,500 and £3,750. For a couple of weeks feeling a bit rough, in a pleasant facility with your own room and en-suite bathroom, that doesn't sound the worst deal in the world!
The money comes from whoever is behind the test. So it may be the developers of the drug, it may be a university, or it may be the people behind Flu Camp itself who run their own experiments.
Can you do more than one trial?
You can take part in more than one trial too. Of course, having taken part in a previous trial limits your options a little as you may now have antibodies that would rule you out of certain tests.
And the staff at Flu Camp monitor volunteer databases to check you haven't been doing too many clinical trials as this may interfere with the results.
The view of a volunteer
A friend of mine, Alan Hunter, took part in a Flu Camp trial a couple of years ago, so I picked his brains on his experiences.
He noted that he had been a little daunted by the prospect of the panel tests as he'd never had to do anything like that before, but was immediately put at ease by how chatty and friendly the doctors and nurses were. The physical tests were fairly mundane; the sort of things most people have throughout their lives (things like blood tests, measuring height and weight, questions about smoking and drinking habits).
When the trial itself began, everyone was extremely professional and far less chatty. In his words: "I preferred that, as I didn't want to feel like I was being treated by Dr Nick from the Simpsons."
Further tests took place prior to the injections and then the vaccinations began with each volunteer injected at 45 minute intervals. Alan's fellow volunteers were all young (plenty of Australians and students apparently) so it was a fun stay.
After the trial had finished he had 20-30 further appointments, ranging from popping in early in the morning to have more blood taken, to having further vaccinations under supervision. He said that if circumstances allowed, he'd be more than happy to take part in future trials.
Would you do it?
With a wife and young child, I'm not sure I'm an ideal candidate for Flu Camp, much as I'd like a fortnight away from changing nappies.
But I can see the attraction. You are testing drugs that have already been studied at length, in a welcoming environment and you get paid incredibly well to do it. But there is also that nagging doubt in the back of my mind. By the very nature of medical trials, there is always some risk involved.
What do you think? Would you give Flu Camp a go? Or is it not worth the money? Let me know your thoughts in the comment box below.