A seat for a motorcycle pillion passenger and a travel version of a bass guitar were among the wacky inventions on show at this year's Oxfordshire's enterprise fair, Venturefest.

The seat was designed by Chris Welford, 18, of the Marlborough School, Woodstock, after he had problems taking his girlfriend on the back of his motorbike.

"I used to take her on the back and when I was travelling in heavy traffic I found that applying the brake put a lot of pressure on my arms, because she was thrown forward."

The seat, which attaches to a normal motorbike saddle, is designed to tilt backwards as the bike decelerates. But he hasn't yet tried it out with his girlfriend.

"Unfortunately, it doesn't work as well as it should. There are faults in the design which could be easily rectified. But I wouldn't want to put her through the test process. I've tried it myself, though."

The travel guitar is the brainchild of Lydene Merry, also 18, of Bicester Community College, who said: "Bass guitars are so large they are difficult to transport." A keen guitarist, she hopes to go on to study sound engineering at university.

Wilson Lau, 20, of Gosford Hill School, Kidlington, was demonstrating his rubbish crusher, which he invented after finding that he couldn't recycle his plastic water bottles because all the nearby recycling facililties were full.

The display by A-level design and technology students was organised by Wallingford company Quincom, founded by businessman Christopher Quinton to research and market new products. As well as software, it is marketing a fridge magnet frame, a sleep aid and fairtrade crafts from India.

Venturefest, which this year celebrates its tenth anniversary, was bustling with entrepreneurs keen to meet business angels and investors with money to fund new ideas or expansion plans.

Those seeking funds included Bicester businessman Charles Boffin, a former NatWest bank executive who has developed an online recruitment system, which is already being used by dozens of large companies, as well as county councils and the Council of Europe in Strasbourg.

He said: "A few years ago, companies were saying online recruitment is undoubtedly the way forward'. Now anyone who isn't doing it will be left behind."

He lives in Southampton, but chose to set up at Bicester Innovation Centre because most of his IT technical staff lived in Oxfordshire. Now he is seeking £500,000 investment to grow his 17-strong workforce.

"We need to grow fast to get to more markets. Large companies which recruit graduates can save themselves immense amounts of time with this."

Another entrepreneur, Bruce Robinson, was seeking £750,000 to expand his Oxford company Mindweavers, which uses cutting-edge neuroscience research by Oxford University to create computer games to stave off dementia, for language learning, and for hearing impaired people.

Ian Harrison, of Oxford-based Alchemy Healthcare, was seeking £300,000 to develop a nasal spray to deliver vaccines and medicines, which is about to be tried out on human volunteers.

Venturefest was also the scene of another competition for Year 12 science, technology and business studies students, modelled on the TV programme The Apprentice.

Natalie Wylde, from Waddesdon School won the first prize of £1,000 and a two-week work placement at Internet registry Nominet, while Rachael Workman, from Didcot Sixth Form, won the second prize of £200.

Peter Johnson, of the Said Business School, who founded Venturefest ten years ago, said: "Getting great ideas into business is more difficult and more random than I supposed a decade ago."

But he said this meant more events like Venturefest were needed.

"While the hurdles have been greater than anticipated, they would have been appreciably higher without the networking support and initiatives such as Venturefest."

Now on sabbatical helping an investment company in Silicon Valley, he said Oxford, its universities and business community were in a fantastic position to foster links between science, finance and business leaders.

Tim Cook, of Oxford University's technology transfer company Isis Innovation, said more than 12,000 people had attended Venturefest in ten years.

He summed up the event's ethos: "Enterprise is all about meeting new people and gathering information."