We’ve reported before about how the escalating war for talent in Silicon Valley is effectively creating a kind of arms race between tech companies.

For example, Google is offering employees a 10% pay increase for 2011; companies like About.me are getting acquired days after launch; and job postings in the IT industry are shooting to astronomical levels. Even Google’s Eric Schmidt has admitted to this battle.

Facebook, Google, Zynga and Twitter are hiring like crazy – and this insatiable desire for staff is likely to spill over into other countries. And perhaps the obvious first target outside of the Valley is London: English speaking, and a magnet for existing tech people in Europe working for US multinationals. And the latest to consider extending its reach there is Twitter.