Not only the Phnom Penh Ladyboys seem to have become more and more in recent years.
Also Sihanoukville seems to pride a lot more Ladyboys, from which a fair share has immigrated from Thailand according to "insiders".
Most Ladyboys in Phnom Penh can be found at the two top nightclubs Pontoon and at Heart of Darkness. But a lot are mingling also with the regular bar girls trying to get some drunk tourists engaged.
Apparently some Cambodian or Thai Ladyboys are not that easy to spot, and especially drunk tourists might end up in a bit of a jeopardy :-)
Almost every Girlie Bar in Phnom Penh seems to host at least one or two Ladyboys.