From a little reading, I know that for $p$ and odd prime, there are two nonabelian groups of order $p^3$, namely the semidirect product of $\mathbb{Z}/(p)\times\mathbb{Z}/(p)$ and $\mathbb{Z}/(p)$, and the semidirect product of $\mathbb{Z}/(p^2)$ and $\mathbb{Z}/(p)$.
Is there some obvious reason that these groups are nonabelian?