Czech President Vaclav Klaus has finally signed the European Union's reforming Lisbon Treaty, becoming the last EU leader to sign the landmark document into law. The treaty can now take effect as of next month.

The ratification unties the 27-nation EU's hands to appoint a new European Commission -- its executive arm -- as well as fill the freshly-created posts of president and foreign affairs supremo.

The Lisbon Treaty is designed to smooth the workings of the EU, which has almost doubled in size to 27 nations since a swathe of ex-communist nations including the Czech Republic joined in 2004.