When using US Airways miles you can open jaw US Airways flights (as mentioned above by MIKESILV and the TPA-CDG, LGW-TPA open jaw) and you can also (for just another two months) book an open jaw using a combo of AA and US miles (I was recently trying to get to AMS or BRU from DCA and the US Airways Intl. Award desk had proposed an AA flight to BRU and a US flight out of AMS). Open jaw - two airlines. Unfortunately, the rest of US Airways partners have to be booked as single airline itineraries. Swissair, for example, is a US partner but you can't book a US flight to Europe and then return on a SR flight - it's all Swissair metal or nothing. Same for using US miles for an award on NW (Asia routes) - all NW or nothing.