If you don't mind getting into CSS you can generate something that looks like a winforms button:
.button {
font:"Microsoft Sans Serif";
font-size:small;
background:#CCCCCC;
border:solid;
border-width:thin;
border-left-color:#FFFFFF;
border-top-color:#FFFFFF;
border-right-color:#666666;
border-bottom-color:#666666;
padding-left:12px;
padding-right:12px
}
Or this which is meant to look like a key on a keyboard:
.key {
font:"Microsoft Sans Serif";
font-size:small;
color:#FFFFFF;
background:#000000;
border:solid;
border-width:medium;
border-left-color:#999999;
border-top-color:#999999;
border-right-color:#333333;
border-bottom-color:#333333;
padding-left:3px;
padding-right:3px
}
To use it just surround the text with:
<span class="button">Button Text</span>
<span class="key">Key Text</span>
I don't think I can post an example here, but if you look here you can see it in operation.
I'll be the first to admit that they're fairly plain, but they do look something like a button ;) I'm sure a little tinkering with the CSS could give better results - particularly if you changed the colours.