I've always wanted to do temporary Pentecost Flame Tattoos with my kids. 

A few years ago, we used sharpies to make some "temporary" tattoos of the Great Commandment circling student wrists like one of those rubber wristbands. The problem is that we didn't have any talented artists among us, so most of the symbols and letters ended up looking like smudges and "prison tats." Nevertheless, the kids liked it.

So imagine my surprise when I saw"Temporary Tattoo Paper" at JOANN's one day. You create a design and text on your computer, print it on special tattoo paper using your standard inkjet printer, then apply with a damp cloth --i.e. just like real temporary tattoos.   (Apparently, this is how many tattoo shops now do it for people who want to make sure before they get a permanent version.)  

Below is an instructional video on YT for using Silhouette Temporary Tattoo Paper.  There are other videos and the transfer paper is widely available.

This would be a fun project for a Computer Workshop or any classroom that had a computer and printer. You can use WORD to create text and insert images. You could print up sheets full of keywords and various symbols, cut them into small pieces for transferring, and let the kids put together "tat words and symbols"  on their forearms.

For the Pentecost Tattoos idea...  Do a Google search for "Pentecost clip art" and you'll find tons of good Pentecost images you can insert into a Word Doc and print on transfer paper.

"Tattoos" (sort of) in the Bible

Deuteronomy 6:6-8  (NRSV)

Keep these words that I am commanding you today in your heart.

Recite them to your children and talk about them
when you are at home and when you are away, w
hen you lie down and when you rise.

Bind them as a sign on your hand,

Fix them as an emblem on your forehead.