Windows has a feature called Extended Desktop which I think is a must-have for people working with the texts of the Bible in general, and Textual Criticism in particular. The feature allows you to view applications on an additional monitor. Digital photographs of manuscripts can be viewed at the same time as digital transcriptions. The setup is ideal for cutting and pasting, developing databases, and writing papers and emails in situations where there is a second digital document involved. The switching between applications which is otherwise necessary only serves to multiply errors and make these processes more arduous. Microsoft has an information/setup page here. Secondary CRT monitors are readily available with the advent of the cheap flat screen, so you can probably do this for free.