This is a nifty trick that changes the colour of your text selection from boring dark blue to any colour you want. Unfortunately it only works for Firefox and Safari :|
Copy this into your CSS stylesheet

::-moz-selection{
background:your colour code;
color:#fff;
}
::selection {
background:your colour code;
color:#fff [FFF makes the selected font white];
}

To see an example, simply select the text in this page!