I'm not sure how long small Pocket Bibles have been around, but the ones below are from the 1800's (except for the ESV).
The one below is one that has fond memories for me because I bought it 20 years ago when I first became a Christian. It came in handy during coffee breaks when discussing spiritual issues with co-workers.
For the word of God is living and active, sharper than any two-edged sword, piercing to the division of soul and of spirit, of joints and of marrow, and discerning the thoughts and intentions of the heart.
Hebrews 4:12 (ESV)