A telephone.
That assumes I know who's responsible in my city for deciding how which hole will get fixed at which moment and that they have valid internal processes to integrate the information into their workflow.
It would be ideal if all the information about city maintenance would go through some Open Street Map based system. See an issue that needs fixing? Load your local city app and make a photo which directly gives the information to the bureaucrat that's responsible for the issue.
If you stand next to a new construction site and you are interest in what's going on, simply getting the information via a smart phone would be convenient.
Yes you could go to the local building administration government building and read the paper documents about what's supposed to be build but that's a complex process.
If you want to engage people political into their local community, than it's useful to make the information about who decides how long a given traffic light shows "green" freely available.
Take an issue like guerrilla gardening. A citizens who wants to make his local community more beautiful plants a few plants that benefit his community. Even if his neighbors support his project, the most local governments are likely to be opposed to plants being planted that aren't in their city planning.
Creating political structures that solve the communication hurdles will require to write code and a lot of smart thinking about how the structures of making political decisions should look like.
Why should the government pay to manage a local park. Why not simply declare everyone who lives within 2 miles of the park as eligible to vote in liquid democracy fashion about how the park should look like and see whether there are citizens you actually have fun maintaining the park as a hobby?
Telephones just aren't good enough technology to manage the kind of information flow that you need for such political processes. Governments want strong neighborhoods were citizens engage but they are not smart enough to produce the necessary systems themselves.
You need smart tech people who come and say: "If you give me a million I can give you a cool way to engage your citizens into having an effect on their neighborhood. The project will seem really cool and modern and visible to voters."
You could even do it as open source, because governments need tech people who implement and integrate the project.
That a much better way to make an impact than on how government works than by become a career bureaucrat because there an enormous power in writing code.
Some remarks relevant to young aspiring entrepreneurs:
Entrepreneurship and age
• In Why to not not start a startup, venture capitalist Paul Graham says he thinks that the chances of creating a successful startup increase with age up to 23 (at least), but that the best way to gain experience relevant to creating a successful startup is to try creating a startup. He suggests that in unusual cases, 16 year olds may be equipped to create a startup.
Whether or not to go to college
• Going to college (especially an elite college) gives one the opportunity to find cofounders and early employees. Mark Zuckerberg met the early employees of Facebook while at Harvard. Drew Houston met a number of the early Dropbox employees while at MIT.
• It's rare for highly successful entrepreneurs to not have started college. Sean Parker (Napster founder & venture capitalist) skipped college but was already earning $80k+/year by his senior year of high school, which is very unusual. See also stay mainstream until you have demonstrated success doing unusual stuff.
• The general consensus in the comments on the Hacker News question To go or not to go college? seems to be that even a highly skilled high school programmer should go to college. However, the remarks therein are not directed at entrepreneurs specifically.
Creating a company while in college
• Entrepreneur Nate Berkopec wrote that an aspiring entrepreneur can learn more through starting a business than through coursework, which is very plausible.
• Entrepreneur Jason Baptiste suggests that rather than creating a company while in college, one should instead work on a less time-consuming side project, and see where it leads.
• If one does find a cofounder and has a promising project, there seems to be little harm in taking time off from college to work on a startup. However, unless one is exceptionally talented, the project probably won't be sufficiently successful so as to furnish a decisive case for not completing a degree.
• In Why to not not start a startup, Paul Graham says that he wouldn't feel comfortable recommending that somebody with a family do a startup. So all else being equal, one should try earlier in life rather than later in life, and this is an argument in favor of working on something entrepreneurial while in college.