There has recently been an online petition constructed for the creation of an independent international committee to investigate 9/11.
But there are some equally worthy ones to sign.
Scrap the planned vehicle tracking and road pricing policy - http://petitions.pm.gov.uk/traveltax/
"The idea of tracking every vehicle at all times is sinister and wrong. Road pricing is already here with the high level of taxation on fuel. The more you travel - the more tax you pay. It will be an unfair tax on those who live apart from families and poorer people who will not be able to afford the high monthly costs. Please Mr Blair - forget about road pricing and concentrate on improving our roads to reduce congestion."
scrap the proposed introduction of ID cards - http://petitions.pm.gov.uk/IDcards/
"The introduction of ID cards will not prevent terrorism or crime, as is claimed. It will be yet another indirect tax on all law-abiding citizens of the UK."
Offer the British people a referendum on continued membership of the European Union - http://petitions.pm.gov.uk/EUreferendum/
"The last referendum on the EU in 1975 asked the public if they wanted to be part of the EEC - a trading agreement between Britain and other European countries. They were never asked if they wanted political integration."
replace the national anthem with 'Gold' by Spandau Ballet - http://petitions.pm.gov.uk/goldanthem/
"We, the people of Britain, feel that our current National Anthem has lost a bit of its sparkle. When we are confronted by the rare occasion of us winning a medal at the Olympics, we all have to mumble through "God Save The Queen", well God help us in 2012! We would thereby like to table the suggestion that we change the National Anthem to something more modern and appropriate and that will re-invigorate our pride. What we specifically want to see, is that the National Anthem be changed in favour of "Gold" by Spandau Ballet. Further, we would like our National Olympic Committee to decree that Tony Hadley is the only person permitted to handle medal ceremonies where the National Anthem is played. We don't mind what he wears when he does this, but preference is given towards a a gold colured suit.
But seriously now, there is also a possibly more important petition than the 9/11 petition, FOR DEBT-FREE MONEY!!
emit debt-free UK notes, repeal the Bank Charters and Acts, call for a participatory and democratic constituent assembly, transfer useful BofE services to public and democratic institutions, withdraw from the IMF, WB, and BIS. Create a public and participatively democratic financial system. - http://petitions.pm.gov.uk/Public-Finance/
"1. Pay off the debt with debt-free UK Notes. As Thomas Jefferson said: "If the US can issue a dollar bond, it can issue a dollar bill". Same for the UK.
2. Abolish Fractional Reserve Banking. As the debt is paid off, the reserve requirements of all banks and financial institutions would be raised proportionally at the same time ...
3. Repeal of the Bank of England Acts and Charters This will remove the private banking monopoly's ability to dominate the money market and give control back to the Department of Treasury
4. Withdraw the UK from the IMF, the BIS and the World Bank. These institution like the Pound Sterling are based on debt control by private banks and unless they too can be reformed they will continue to create the debt lock. They are not needed for currency exchange either.
5. All decisions and appointments should become public.
Supply should be kept slowly based on population growth and purchasing power."
This is just a tiny sample of petitions, some extremely important affecting the whole world and international affairs, some not as important affecting only a handful of people.