@ajalkane
check this app:
http://my-meego.com/software/applica...Auto=594&faq=1
"This app will run in the background and store the last tag type and UID for you. "

i don't test it so i don't know if don't show any kind of messange when running in background you tag

i don't find the link to the source code , i just find this at google:

http://projects.developer.nokia.com/nfcinfo/

but i think not the same app.