Apparently, since we've switch from "you have to have sighted the moon" to "it's ok to use big fancy math" systems for determining the Islamic calendar, we can now plan well in advance for Ramadan and Eid-al-Fitr (Lebaran to my Indonesian wife and friends):

Facebook | Islamic Society of North America (ISNA)'s Notes:

Ramadan 1429: September 1, 2008

The Astronomical New Moon for Ramadan is on Saturday, August 30, 2008 at 19:58 Universal Time (i.e., 3:58 pm EDT, and 12:58 pm PDT). According to the criteria adopted by the Fiqh Council of North America, and European Council for Fatwa and Research, [the conjunction before sunset and moon setting after sunset in Makkah] first day of Ramadan is on Monday, September 1, 2008.

Eid al-Fitr 1429: October 1, 2008

The Astronomical New Moon for Shawwal is on Monday, September 29, 2008 at 8:12 GMT, 4:12 am EDT, 1:12 am PDT). According to the criteria adopted by the Fiqh Council of North America, and European Council for Fatwa and Research, the first day of Shawwal is on Wednesday, October 1, 2008.

Also posted to the Fiqh Council's website.

Update: IMAAM agrees, as does ADAMS.