Also, somewhat O/T but I recently read a very interesting article written by Alex Stein about how the right to silence actually helps the innocent. Juries will assume that many defendants who take the stand will lie (to save their own butts)- so there are 2 pools of defendant/witnesses: those who testify truthfully and are innocent, and those who testify untruthfully and are guilty but lying. Since defendants can plead the 5th and not testify, juries know that some people who are guilty won't testify. Because guilty people have that option - and it seems more reasonably to just not testify than risk lying and messing up - jurors look at those who DO testify as more likely to be innocent than they would otherwise. This gives the innocent a higher probability of being believed.
Its a little confusing, but very interesting nonetheless. And in all these years, I never, ever thought of it- I always thought the right to silence only helped the guilty (thinking- if you were innocent, you'd testify!)