How to check BTC transaction when buying face to face?
Does your cellphone have a web browser? There's many good web wallets (such as https://greenaddress.it/en/) which would allow you to simply open it in a web browser. If you don't have QR code capabilities, then your only resort is to have him/her write your bitcoin address, character by character. Once (s)he's sent the bitcoins, your web wallet will alert you that it's arrived and you're good to go. You must of course have an internet connection on your phone.

PS: if it's a large amount of money you're transferring, you should probably wait 10 mins or so to get at least 1 confirmation.