TypePad, the weblog hosting service I use, has created a new feature called "Tip Jar." I have long had a PayPal link in the right column for those who want to pay for my services. The Tip Jar is a more elegant solution and I'm pleased to use it instead of a direct link to PayPal.
I bill $60 per hour for the technology coaching services I offer, but I only bill for the time I am on site coaching a client. When someone asks for assistance by posting a comment here, sends me an email message, calls me because they are having a problem or to ask a few questions, I assist without billing for my time.
You can use the Tip Jar to make payment on an invoice and you can also use the Tip Jar to give me a small tip. If you have a PayPal account, you can use it via the Tip Jar. If not, you can handle the transaction with a credit card. I appreciate your support of my efforts.