Your image (picture at startup)

A lot of people would create a custom screen identifying them as the owner of the unit and it stayed on display when the lock code was requested.

Sample:

http://mynuvi.xoom.it/auto_splash/nuvi_garminlock_new_EN.jpg

I know turboccc has a program to change the Garmin logo to include ownership or whatever.
Good idea.

You are not the last one, I must be!

Just load any picture you want to what ever file you use to send PIO's to your unit. Size the picture to the right size, when you hook the GPS to the computer just send the picture to the GPS. On the GPS, goo to settings and pick "display" go to "splash screen" hit "change". On the "350 nuvi" go to "view images from internal storage. You should see the picture you sent. Just touch it and follow instructions.

My nutty friend has a picture of his dog making a mess on his neighbors lawn.

The Nuvi 2595 isn't set up that way, no "splash screen".
That's why you go to the image file. I guess Garmin has to change something. LOL

I guess that's the price we pay for quick start.

I have my granddaughter on my wife's splash screen and on one of my daughter's I have a photo of me pointing, at her, to behave and drive safe.

She said, "Daaaad?"

I don't spot support under the Tools|Settings|Display for user splash screen on my 3790LMT.

However there is a function they call wallpaper.

Tools|picture viewer
then select a picture in the picture viewer interface by touching it, the select the horizontal bar menu and activate "set as wallpaper".

The instructions assert that the unit displays your wallpaper when it wakes up from sleep mode.

On connecting my 3790LMT by USB cable to a PC, I noticed that the pictures offered to you in the picture viewer are stored in the pictures directory at the root of the "drive" as seen from the PC.

I used Photoshop to prepare a portrait and a horizon formatted picture from a south American trip to 480x800 pixels (the resolution of the 3790LMT screen, I think), and stored them to that directory.

Using Tools|Picture viewer I was indeed offered my own pictures after the dozen Garmin had already placed there. Selecting one, and then using Menu bar|set as wallpaper turned out to be not quite enough. After a pause you are offered the chance to adjust your wallpaper picture (zooming and panning, basically). Even if you don't want to adjust it, you need to select the "save" button from that option, or it will leave your previous setup in place.

But, in the end, it appears in my normal use pattern I will hardly ever see this wallpaper. It does appear if the unit is unplugged from both the auto power cord and computer USB cable, and turned on with the power button--where it appears as the backdrop to the lock symbol and the advice to touch twice to get going.

But this is a nearly useless unit for out-of-car applications, so that is not condition I reach with appreciable frequency.

My picture is of my wife and I sitting near a waterfall in Vermont.