Dear Jarek,
Here is a selection of suggestions --- any one of which could have a background picture.
"Master Key Phrases!" (Gold Master Key)
"A Bunch of Key Phrases!" (Bunch of Keys)
"Telling Phrases!" (Silhouette Head, Speaking)
"Hot Key Phrases!" (Computer HotKey)
"Coin a Phrase!" (Large Gold Coin)
"Wanted! Capture a Phrase!" (Wanted Poster with Prison Bars)
"Colourful Phrases!" (A Multi-Coloured Poster)
"Handy Phrases!" (A Large Hand, Full of Slips of Paper)
"Beautifully Phrased!" (Pretty Girl Speaking)
"Catch A Brilliant Phrase" (Sports � Person Catching a Ball)
"In Praise of Phrases!" (A Crowd Shouting �Hurrah �)
I hope that these ideas help to stimulate your brain cells!
Les