I used to have a tachometer CPU monitor back in the Athlon XP/Nforce 2 days. Someone was selling a kit that connected via Serial port, (Don't even think modern Mobo's have serial ports).

My 16 year old daughter sent something like 15,000 in a month once. I don't remember the actual total, but we did the math and it equaled out to one SMS every 3 minutes, 24 hours a day for an entire month. Thank god it's an unlimited plan.