Windows PDA offers Skype: "[On the Asus P505] main menu [there was] was a client for Skype’s Internet based voice technology....The P505 is actually a tri-band GSM handset (so it works in the States). In theory, you might just get away with running Skype over GPRS.
However, Wi-Fi would be a more sensible solution and the INQ notes that it is mentioned in the list of compatible accessories. Presumably Asus can supply a SD card style 802.11 interface for the P505."