cheap airfare to Siem Reap
FYI, a year ago when I was there, I bought a 4-leg airpass on Bangkok Air for $275. This covered TWO round trips for me: Bangkok to Siem Reap, back to Bangkok, Bangkok to Koh Samui, Koh Samui to U-Tapao (closest airport to Pattaya).
Overland Phnom Penh to Siem Riep
the bus ride is about 5 hours - leaves from near the central market in pp and arrives at the bus station in sr. a bit boring but nice countryside. one or 2 [url=http://isgprohibitedwords.info?CodeWord=CodeWord134][CodeWord134][/url] stops enroute (no on-board lavs). take a lunch
there were some cambodian airline service with propjets from pnh-sr but that might not be avilable now. depending on your itinerary, 1 night would probably not be enopugh in sr - if you are going for hobby, you would actually be better off going to snooky (4 hour bus ride) - no other way there from pp. sr is only valuable as a cultural trip to angkor (which takes a whole day by itself - minimum)
Cheap airfare to Siem Reap
Flying to Siem Reap was a reapoff in the past, especially from Singapore where SilkAir had the monopoly.
But now the things has changed. Jetstar Asia, a subsidiary of Quantas, started flying Singapore-SR route three times/week. Round trip, restricted tickets, will cost you around S$210 including taxes. Jetstar Asia also fly to Phnom Penh and you can buy one way ticket to either places. So you can buy SIN-PP and SR-SIN ticket for S$210 and make an overland transfer between PP-SR. Just my two cents.
Kamking1