Has anyone of you created one or are there available implementations?

I am developing an app that uses 'labels' a la Gmail and I am looking for a easier way to apply multiple labels to a given item.

Wouldn't a google suggest mechanism be better? Tags taken from a checklist aren't really tags.

Hmm... the supplier list is being added to, there are fields such name, address, email, sales tax number, negotiated credit period, etc. Now this supplier supplies us with products A, E, M, Q, T, AW and HJ. I wanted to have a screen estate friendly way permitting entering multiple data from a list of around 175 items. Something like Google Suggest keeps changing available options whereas for this I need all options available throughout.