The original answer is no longer working as written:
<%=Html.TextBox("test", new { style="width:50px" })%>
will get you a text box with “{ style=”width:50px” }” as its text content.
To adjust this for the current release of MVC 1.0, use the following script (note the addition of the second parameter – I have mine starting as blank, adjust accordingly based on your needs):
<%=Html.TextBox("test", "", new { style="width:50px" })%>