  We introduce particle phenomenology on the noncommutative spacetime called
the Groenewold-Moyal plane. The length scale of spcetime noncommutativity is
constrained from the CPT violation measurements in $K^{0}-\bar{K}^{0}$ system
and $g-2$ difference of $\mu^+ - \mu^-$. The $K^{0}-\bar{K}^{0}$ system
provides an upper bound on the length scale of spacetime noncommutativity of
the order of $10^{-32} \textrm{m}$, corresponding to a lower energy bound $E$
of the order of $E \gtrsim 10^{16}\textrm{GeV}$. The $g-2$ difference of $\mu^+
- \mu^-$ constrains the noncommutativity length scale to be of the order of
$10^{-20} \textrm{m}$, corresponding to a lower energy bound $E$ of the order
of $E \gtrsim 10^{3}\textrm{GeV}$.
  We also present the phenomenology of the electromagnetic interaction of
electrons and nucleons at the tree level in the noncommutative spacetime. We
show that the distributions of charge and magnetization of nucleons are
affected by spacetime noncommutativity. The analytic properties of
electromagnetic form factors are also changed and it may give rise to
interesting experimental signals.
