I save a layered Tiff (background and text) and then I can open and drag and drop the text layer onto other images.
i save as a simple layer psd. that way i can always edit the text later....
Even better: Photoshop CC 2014 can now store assets like text objects via the new Creative Cloud Libraries. Once they're in there, you can just drag and drop them onto a document.
@FloorCoach: You might be able to do it on Android via Photoshop Touch, however, there's a couple things to note: PS Touch doesn't have a huge list of fonts to work with. You'd probably have to create "template" projects with the different comments in each. But you'd be able to export the work to desktop Photoshop and change the text there to a font you want.
You could use Creative Cloud to store text assets as I noted before but PS Touch doesn't see the Creative Cloud Library assets as of yet. PS Touch does import PSDs but they'll be flattened so that's not really a flexible option when it comes to text.
That's interesting to know...
Leslie Wand - Tiff actually allows you to edit text later as well.