I use the tags in the link below from Lee Valley Tools. They are 9.95 for 50 of them. The copper tags can be written on with a pen and the engraved words stay forever. I then wrap the copper wire around a 4 inch galvanized nail and stick it in the ground. A cheap tag that lasts forever...unless it gets stolen ;)

Here is a link that might be useful: Copper Plant Tags

I use scissors to cut aluminum soda cans in similar shapes (Cut one end in a point and poke the tag directly into soil) and then write with a ball pen. The engraved words stay forever and it costs nothing.

Why don't you just paint the names on flat rocks or stone to add to your garden? Paint takes forever to fade.

I truly love the idea of painting on rocks. That is brilliant. Thank you Sunkeeper. I think that's what I'll do.

If you coat your rock labels with outdoor varnish after painting the names, they'll last even longer.

I cut horizontal blinds into 4" pieces and use those. You'll get hundreds from just one blind.

I also use cut up venetian blinds. I then write on them with felt pen......

I have been buying white T plastic name tags at the Dollar store. They are 10 for $1.00.

Some one told me they use plastic knives stuck in the soil. Those would be even cheaper :)
What do you all use to write on the blinds that will not fade ?

I started using broken pieces of terra cotta pots last year, with acrylic paint. Your can use a drill to make a hole (slow and easy does it), and then use some stiff wire to make a hook, or larger pieces could be set in the ground.
I sealed them with varnish and urethane, but can't remember which was which, and one didn't work! Oh well.

They look pretty neat.