{{sup|Text to be superscripted}} produces: Text to be superscripted
This template is listed at Wikipedia:Subst as a good candidate for substituting (i.e. {{subst:sup}}). On a page that uses the template many times, however, this is likely to clutter and lengthen the page significantly.
Text can also be superscripted simply by using the <sup> and </sup> tags, so that:
<sup>Text to be superscripted</sup> also produces: Text to be superscripted
for inline formulas, to get a better matching font size and vertical alignment than with \textstyle (or the \scriptstyle kludge) PNG-rendered TeX formulas