Starwood Preferred Guest members can earn double or triple points for stays at participating hotels through Dec. 18, 2011. Members who register and complete an eligible stay will earn double points. Stays that include a Sunday or Thursday night will earn triple points. Registration is required at http://www.spg.com/tripleup and members will earn the bonus on all stays completed between Sept. 6 and Dec. 18 as long as you register by Nov. 15, 2011. A total of 875 properties worldwide are participating and a list of 225 non-participating properties are located at spg.com/tripleup. Over 80 non-participating properties are located in the U.S. so be sure to check the list before making reservations. Regular members who earn double points will earn a total of four points per $1 spent on all eligible charges and elite members will earn five points per $1 spent. If your stay includes a Sunday or Thursday night, you’ll earn a total of six points per $1 spent and seven points per $1 spent if you’re an elite member. Bonus points will post to your account within two to four weeks after the stay and there is no limit to the number of bonus points you can earn.