The greatest thing to happen to
money since the invention of the
debit card.
PayPal is now a service of
X.com, and is a quick'n'easy way of sending money to anybody with an
email account. Extremely
popular on
eBay and other online
auction sites because of its speed and
simplicity.
The process works something like this: You sign up and include a credit card number (which can be validated immediately) and/or a bank account number (which takes a bit longer to validate by snail mail). No other fees or charges apply, period.
Once you've done this, you can send money to anyone else with a PayPal account. To make a payment to someone, money is automatically charged to your credit card, unless it's already been transferred into your PayPal account from your bank account at your request. When you are sent money from another PayPal user, you can either transfer it into your bank account or save it to pay to someone else later.
If you want to send or receive money from someone who's not signed up with PayPal, they get an email inviting them to join, with a five dollar incentive for both of you. And there's never, ever a charge for these basic services (only for more advanced ones) -- PayPal makes money by keeping the interest from the money in your account.
Finally, speaking as a web developer, I love their Web site. It's a model of e-commerce because of it's sheer simplicity -- you log in, you send or get money, you log out. The forms are easy to use, the design is simple and uncluttered, and on the whole it's a delight to use. Every online bank should be this easy.