Planning your summer holiday but can't decide on anywhere that really takes your fancy? Flicking through travel mags is always the same: sun, sea and sand...Been there, done that...Well, if you're looking for extraordinary and out of this world holiday ideas, you should definitely find something in this list that will blow you away!1) Celebrate Christmas...In July. Maybe, like me, you feel Christmas passed you by far too quickly this year. So why not celebrate it again in a few months? December falls during the summer down under, so unsuprisingly BBQs and bikinis often replace the roasts and reindeer jumpers. Some Aussies who wanted the traditional stereotypical image of a white Christmas started a new sub-tradition of July festivities in the Blue Mountains of New South Wales. 2) Bathe in a mud volcanoI don't just mean a mud bath - I'm talking about diving into the crater of a genuine mud volcano!This rare phenomenon forms when natural gases below ground force mud slowly upwards in warm, sulphurous bubbles. Over time a hard outer cone develops around the central crater, mqking it a perfect bath tub for soaking in ;)You could try the El Totumo volcano in northern Colombia. This 15-metre high volcano is filled with mineral-rich goo of just the right consistency to allow you to lie or even stand in it without sinking. Have fun scrubbing all that muck off afterwards...3) Volcano SurfingForget windsurfing and snowboarding...Now you can surf in the silky-soft and still-warm ash of an active volcano - a far more exhilerating experience! There's no denying it can get a little dirty, but nothing can match the mud volcano...Cerro Negro in Nicaragua is Central America's youngest volcano, so would be a good location to try ash-boarding. A guided two-hour hike up the 728-metre-tall volcano brings you to the red-hot crater, from where you can cruise down its gently smouldering flank on a plank of wood with a sheet-metal base, at speeds of up to 50mph. 4) Soak in a Beer BathCraving a pint? Why not have a tub-full? Austria, Germany and the Czech Republic have a growing number of brewery spas, so make your fantasy reality!The vitamins and yeast in beer are supposedly cleansing for the skin, so the Landhotel Moorhof, just outside Salzburg, Austria, fills tubs with beer and offers a four-course beer-themed dinner, including beer soup and even beer crepes for desert.However tempting it might look, I'm not sure I'd want to be drinking any from a tub that hundreds of others have bathed in though...eughr! 5) Train as an astronautAdmit it, you've always wanted to take a little trip to the moon. Don't we all? Well now you can get one step further...Take an astronaut training course at Nasa's flagship base, the Kennedy Space Centre. You'll receive intensive tuition and tackle mission simulations, and even meet a veteran Nasa astronaut. The two-day programme also lets you build and launch your own rocket and dabble with a fully outfitted mission control. Or, what about a full-on zero gravity flight? Sorry, but that's probably the closest you're ever going to get to real space travel... 6) Snake MassageLet snakes slither and slide all over your naked body as you lie motionless, enjoying the cool, slippery texture of their scales...Most people's worst nightmare, but apparently extremely effective in soothing aching muscles and joints. Barak's Snake Spa, in the village of Talmei Elazar, Israel, employs various (non-venomous you'll be glad to hear) snakes as masseurs. If you're brave enough to try, let me know how it goes...and if you make it out alive! 7) Glow-worm TubingWaitomo.Explore New Zealand's magical underworld of glow-worm caves, chambers lit solely by a mass of the bioluminescent bugs which dangle from the roof in long, stunning strings.You can either take a boat or, for something a little more out of the ordinary, hop into an inflated rubber tube and navigate your own way through a maze of caves, past underground waterfalls and stunning rock formations. 8) Star in a Film Fulfill your life-long dream of being in a Hollywood production...Simply check into the Peninsula Beverly Hills hotel (yes it will cost you an arm and a leg, but you might even catch a glipse of some stars!) and arrange with the concierge to have an Emmy-nominated producer and crew spend a day filming you doing whatever it is you like. They will then edit the footage into a professional-quality DVD as a keepsake.Unfortunately you're not going to get paid for it (in fact it will cost you at least £1500, and that's without the hotel), but who knows, they might see how super-talented you are and ask you to be in their next production... 9) A Flirting TourTake a 'Flirting tour of London' with relationship and flirting expert, Jean Smith. She sweet-talks her way through cultural hotspots in central London while also tutoring tour members in the fine art of dalliance. The tour lasts 90 minutes and includes flirting hot spots such as art galleries, bookstores and supermarkets. Perfect for those visiting London in the hope of having a little holiday romance. Learn to do it London style ;) 10) Spa ClubbingGuys: you get a club full of half naked girls. Girls: you don't have to bother with dresses or make up. It's a winner all round really. There's still the club beats, the dancing, the strobe lights and the flirting...just all in the mineral-rich thermal waters of Budapest's traditional bathhouses! This would certainly make for a night to remember.