I'm sorry if it's a repost, i couldn't find anything resembling it
Anyway, i've heard that in Arena for example, you can use your mend pet ability to store charges in the Vial of the Sunwell trinket Vial of the Sunwell - Item - World of Warcraft
This can be very useful obviously for the instant heal, and the mana regen the trinket gives is always useful.
Edit: Works with rank 1 mend pet