[danik.js]

Вот на css3:

<style>
div{
    position: relative;
}
input{
    -webkit-animation: diagonal 2s infinite forwards;
    animation: diagonal 2s infinite forwards;
    position: absolute;
    top: 0;
    left: 0;
}
@-webkit-keyframes diagonal{
    50%{
        top: 150px;
        left: 150px;
    }
    100%{
        top: 0;
        left: 0;
    }
}
@keyframes diagonal{
    50%{
        top: 150px;
        left: 150px;
    }
    100%{
        top: 0;
        left: 0;
    }
}
</style>
<div>
<input type="radio">
</div>