As a loner to improve the world (a little) or inspire it: it is possible. Lots of examples. (Which we 'll get to. Various)
But several together is just finer and more efficient, easier, has more impact and you can build on the experience of others. You can invest your commitment, and find like-minded people.

cooperativesEveryone is responsible for his own actions and their consequences. At greater risks, it is useful to (insure or) protect individual by operating under another legal status. Or to join existing groups. In a group with no legal structure, each one is individual liable. That responsibility can (mostly) be limited to the assets of the organization by establishing a non-profit (non-profit organization) or a foundation.
(A non-profit organization may make profit, but not pay it to the members. NPOs exist with hundreds of employees.)

To form quickly and cheaply is the LTD (UK Limited). There are firms that make (including address and account in England) it in one day (through acquisition) for your.

The cooperative (or coop) is a participative and democratic organization of producers and / or consumers, like-minded people who exploit economies of scale. It provides good protection of private property and liability.

(Citizen) cooperatives that emerged from a social movement have some values in common ​​that are reflected in the 7 ICA (International Co-operative Alliance) principles:

1. Open and voluntary membership for all without any discrimination
2. Democratic member control: participation, equal suffrage and accountability
3. (modest) economic participation of members, value for approved developments
4. Autonomy and independence, in partnership
5. Education, training and information for members, staff and the public
6. Cooperation among cooperatives
7. Commitment to community

Phone companies found the village too small and faraway. The 640 inhabitants of the German Löwenstedt started their own cable company, Citizen Band Build Netz. They gave 100 euros for a share and lend their company another 900. They laid handedly 22 km fiber optic cables for their broadband and Internet access.

Since 2013 stays at the Old Jail Hasselt 'University for Social Interest' as a third core mission of a university( since the founding of the University of Bologna (1088)), namely social services (in addition to research and teaching). It brings together NGOs and grassroots groups to encourage processes of social change. Key themes include poverty fighting, development, environment, climate, peace, social cohesion and dialogue between worldviews. There is input from provincial government, the PXL - College and many volunteers. A turntable platform and exchange point for engagement. Each college would have to give its severity to such an initiative.
(An NGO (non - governmental organization) is independent of the government and operates about a public interest: environmental, health, development...)

Many cooperative society innovative initiatives gather their activities on a social calendar on internet, which greatly increases accessibility and sharing.

Transition towns are local communities that make their own way of working and living more sustainable. Important drivers are climate change, the depletion of fossil fuels and raw materials, oil and others. Initiatives include reducing energy consumption, sustainable (energy) production, local and environmentally friendly cultivated food, healthcare and education organization (focused on self-sufficiency).

Many initiatives operate together under the umbrella of TT. An exciting platform full of inspiration and links.

Occupy Wall Street started in 2011 as a protest movement and found many adherents worldwide in (mostly Western) cities. Binding elements are discontent with economic inequality, the breakdown of social and economic achievements, power and abuses of banks and multinationals, and the (alleged?) invisible power of 1% on the political decisions that threatens democracy (cheatens?). We are the 99% is their known slogan.
Find them on sites en facebookpages.
A total lack of organization does not seem conducive to the achievement of objectives, the enthusiasm faded, but there are still remnants and active contacts.

Anonymous is an unstructured Internet community protesting anonymous and responding to abuses, often by hacking websites. A digital anarchist movement without leaders or members, where everyone can join. They support various alternatives. The Guy Fawkes mask is their symbol.

Internet offers endless possibilities to disseminate ideas and work together. For the desired subject, look for the consultation, the federation, cooperative, star pages, links or dome (fill in: childcare, social employment, allotments, squatters, bio gardeners...)
Facebook or Google Sites, you can easily and free make a web page or site yourselves.

Avaaz is an Internet community since 2007, active in the field of global: climate change, human rights, animal rights, corruption, poverty, and conflict. It aims to bridge the gap between the world as it is and the world as most people want it to be. Online petitions, videos, model emails to send to deployed leaders and politicians are used. Often activism scuttled to klickionisme. Of course you can choose which actions you support.

But local anchoring, the support of the neighborhood is at least as important and necessary as the (expertise) networks. Virtual digital actives call it IRL: In Real Life. Put your lights on in the neighborhood committee, the neighborhood council, the cultural council, an information evening, Open Door, philosophical café, old pub, folklore market, community development platform... Hang a note in the corner store. In practice, make your actions better personal and small, with roots in homegrown. (This does not exclude solidarity with counterparts, and all over the world.)

Courses attract like-minded people. Information and training should be for everyone a right. Prices for "alternative courses' make me sometimes frown eyebrows. If rates tend toward commercial, making needy are excluded (by gooders!), I have my reservations.

(Poverty connection, consumer net, sustainable mobility,….)