Like the title says, you can now configure your WORKetc system to accept payment through PayPal Payments Pro, or Express Checkout.
Head on over to
Settings > Merchant Integration to configure your Express/Pro PayPal Integration mode. Naturally, Website Payments Standard is still available.
Express Checkout is available to any PayPal business, all you have to do is create some API credentials as in the example below:

Once this is all configured, your clients can pay you through your secure customer area.

Testing the comment thing...
How can my client know how to get to the Secure Customer Area?
Should a link be provided by default?