From Alexey Iljin:
Client for Google Translate is a free translator for Windows which enables the fast translation of text in the majority of applications, such as Outlook, MS Word, Internet Explorer, and Firefox using the Google Translate service. Now you can translate web-pages, electronic mail and other documents without opening online-translation sites and buying expensive bulky programs. This free translator is always at hand - you simply need to select the text with your mouse. Additional features: Learning foreign words, Supports Wikipedia articles, Supports free XDXF dictionaries.