It could turn out to be the world's longest graffiti space -- the massive concrete barrier separating Israel from the Palestinians.

Over the Internet, a group of Palestinian graffiti artists is offering to spray-paint your personal message on Israel's towering security wall in the occupied West Bank.

It costs 30 euros ($40) per message and they can be as solemn or wacky as you want. Everything goes, except for obscene, offensive or extremist hate speech. Clients get three digital pictures of the finished product.

The 8-meter (25-foot) high barrier of massive concrete slabs is part of a 620-km (385-mile) fence Israel says is intended to keep suicide bombers out, and which can be dismantled at some point in the future when peace reigns.

But with its slit-eyed watchtowers and burgeoning Palestinian protest graffiti, it is already reminiscent of the hated Berlin Wall, which divided the German capital for 28 years before it was torn down 10 years ago.

The taggers at are members of the Palestinian Peace and Freedom Youth Forum, which set up the scheme in collaboration with a Dutch Christian organization.

It is a new way to speak with the people, that we the Palestinians exist, says graffiti artist Yusef Njm.

We are not only throwing stones and clashing. We are alive. We think in a new way to tell them that we are alive.

Organizers stress that revenue does not go to buy weapons for the Palestinians. It is intended to support grassroots social and cultural projects in the West Bank.

(Writing by Douglas Hamilton; editing by Michael Roddy)