I've tried the following with quite great success in chrome
$("input.focus").focus(function () {
var val = this.value,
$this = $(this);
$this.val("");
setTimeout(function () {
$this.val(val);
}, 1);
});
Quick rundown:
It takes every input field with the class focus on it, then stores the old value of the input field in a variable, afterwards it applies the empty string to the input field.
Then it waits 1 milisecond and puts in the old value again.