Now that the PSP Minis have been launched, there's going to many more reasons to check out what's going on on the PlayStation Store.

And that means you'll eventually end up buying stuff, too.

Of course, in order to do this you'll need to make sure you have cash in your PlayStation Store Wallet.

There are a couple of ways to do this. Let's show you how.

I'm about to buy a PlayStation Mini game: Bloons.

However, I've only get 54p in my Wallet, as you can see from the top of the screen. The game costs £3.49 so I'm going to have to add funds.

The simplest way to do this is directly when buying a game. For example, once you've added details of your credit or debit card into the system, the system will automatically choose the minimum amount of money required for the game you want to buy.

The PlayStation Store only works in terms of fixed amounts: £5, £10, £20, £30, £50 and £99.46.

You can also add funds from outside of the PlayStation Store, however, which is useful if you want to limit how much money a child can spend, for example, as the system is password protected.

To do this, choose the Account Management option from the PlayStation Network icon, which is on the far right of the PSP Crossbar.

Then you want to select Transaction Management.

From the next menu, select Add Funds.

This provides you with the various amounts you can add to your wallet. I'm going for £15.

Now when I go back into the PlayStation Store to buy Bloons, you can see the amount in my Wallet has been updated.

You are also sent an email notification of the amounts added to your Wallet.

That's it. Don't miss our How To guides for PSP, as well as other portable platforms.