There'll be lots of texts flying around filled with Christmas greetings, but getting a message from Santa is much more impressive than getting one from someone you know. The Santa SMS service lets you schedule an SMS from Santa to surprise your loved ones.
The site is very straightforward to use: just enter the number, a message of up to 160 characters and a suggested time when you want the message to arrive. (You can also schedule it to be sent immediately, but having it show up first thing on Christmas morning is much more impressive.) If you can't think of something witty to say, there are also preset messages available you can copy from the site.
The sender of the message will be identified as Santa, so no-one will know your involvement. The service costs $3.00 per message, which you can pay for via PayPal.
Santa SMS was built by Omnissient, the same team which created Fyels, a Lifehacker favourite for easy file sharing. Fyels has fans in other places as well -- it is used by the Nepalese government and was favourably reviewed by the Wall Street Journal.