How to travel from London Heathrow to Eurostar Train in Ashford UK

Say you want to take advantage of the Eurostar train from London to Europe, how do you get from Heathrow to the train? Aside from booking a limo, if you want to use public transportation, take the Underground (details here) to Kings Cross / St. Pancras Station, for 4 GBP, and then take National Rail the rest of the way nationalrail.co.uk for 23.70 GBP. Prices as of 18-Apr-2009.