How can I get a servicemark in latex?

I looked at Will Robertsons answer to Entering Unicode characters in LaTeX which explains how to enter a unicode character but it uses \textemdash and I don't know if a LaTeX command exists.

The unicode number is 2120 and it looks like:

Some service℠

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Why not just use Some service$^{\textrm{\scriptsize SM}}$ that you can make into command like, say, \smark and use Some service\smark? – Werner Jan 17 '12 at 21:07
\textsuperscript{\scshape sm}? – egreg Jan 17 '12 at 21:14
Werner: it has to be one char like the TM symbol. Egreg: the level of the text isn't right. It should be the same as the TM symbol but with an S. – Jonathan Evans Jan 17 '12 at 21:25

Have you tried \textservicemark, a macro provided by the textcomp package? Its output looks like this:

Addendum In your comment, you mention you'd like to use Minion Pro as the font. Assuming that you can run either xelatex or lualatex on your system, the following MWE shows how you might get a Service Mark symbol (set here in "Myriad Pro", a sans-serif font which often accompanies "Minion Pro"):

\documentclass{article}
\usepackage{fontspec}
\setmainfont{Minion Pro}

Two comments: (i) It should be "sm" and not "SM", right? (\scshape has no effect on uppercase letters.) (ii) Do you need the \thinspace? – Mico Jan 18 '12 at 15:45