I've seen a Calor bottle made into a chimenea type thingy, using a bit of lorry? exhuast pipe as a flue.
I've found a battered (i.e. dented, valve guard cut off, valve unscrewed/ removed) rusty old 15 kg bottle in a ditch. Tempted to set to with an angle grinder and make me a little brazier.
Any other ideas?