Garbage eating Pigeons

The pigeon is ubiquitous in the world's cities due to a similarity to the native habitat of these birds -- seaside cliffs in the middle east. We humans went and built these cliffs everywhere, and even leave around half-eaten sandwiches for sustenance. If there weren't cars and cats and predatory hawks, pigeons would think cities were perfect.

One thing that annoys me about the city is litter.   I often see little bits of garbage thrown into some corner where it will just kind of sit around for all eternity.  Occasionally I've gathered it up and thrown it away myself, but within a week's time, it's back.   This gave me an idea.

Using the de-extinction technology I mentioned earlier, I make an artificial variant of the pigeon.  This species will have digestive enzymes that can consume paper, plastic, and styrofoam.    I'd like to include glass, but glass is made of pretty much pure silicon dioxide, and there are limits to what protein can accomplish.   I engineer 20 of these, and release them in a major city, ideally one with an extreme litter problem.

The garbage eating pigeons will clear the streets quite handily.   While existing pigeons will go to extreme lengths to grab old bits of bread and discarded lunch things, such as jumping into dumpsters, charging across five lanes of traffic, and I even saw a pigeon try to divebomb a sandwich out of someone's hands once.  (This failed.)

So when pigeons can eat stuff that's just lying around, I imagine it'll be snapped up in a matter of weeks.  At which time they will move on to dumpsters and landfills, lowering disposal costs.

Of course, there's a catch.  No organism is 100% efficient, and birds poop.  Birds in fact have an annoying instinct to poop into puddles to disguise their trail from predators, and when airborne often confuse shiny cars with puddles.   This is going to mean a greatly increased bird population in the city, and with it, greatly increased car washing will be required.   I may be able to breed a new instinct into them to poop into grass instead, which would fertilize the grass.

And if they get too numerous, there's another creature from their native habitat that also does well in cities, the Peregine falcon.   This is the fastest moving bird on earth, and exclusively eats other birds.   It enjoys pigeons for dinner the way that I enjoy a medium-well steak.  Each released falcon will eat a minimum of five pigeons a day.

Safety Twitter

To some degree, crime is a communication problem. Crime used to happen mostly in the gloom of night, or otherwise when no one was looking. See, responsible social people dislike it when people are victimized, and have formed organizations that punish offenders. In modern times, this is the police and courts. Police halt offenders in their tracks, and turn them over to the court system for punishment. So to successfully commit a crime, one must keep the police unaware of it.
So Discovery news reports that a think-tank imagines a Twitter-like interface (possibly even twitter itself), in which people can anonymously report the locations of crimes, which will rapidly attract police attention. If enough people keep this up, crime will effectively be impossible. Fairies dance and unicorns sing in Utopia.
Of course, a big rub that Discovery points out is that humans are not cyborgs that can magically connect to the internet. Crime is most common in neighborhoods where people can't afford expensive electronics, and the obvious answer of public terminals attracts vandalism. (There are some people out there who just love to ruin things for other people, even if they get no direct benefit from doing something like that. Give a street a public terminal and inevitably someone will doodle on it, someone else will pee on it, and someone will use it to look up porn, even if 95% of the other people use it responsibly.)
Another approach has been the UK's plastering of ubiquitous cameras. From what British people have told me, that did not work. People resented the cameras, especially because the government took an obnoxiously paternal approach to objections. (Namely, "It's for your own good, now STFU.") Crime did not noticeably reduce, as the local thugs took to wearing face-obscuring garments like hoods, and the cameras got endlessly vandalized by angry citizens.

Litter Collection Bot

The city in which I live is clogged with litter. As far as I can tell, some moron gets drunk and decides that throwing crap out his car window is disposing it. Also, I occasionally find tires where somebody has decided that since disposal costs are so high, that the best thing to do with their worn out tires is to toss them where no one will notice. Someone does eventually notice, but by then the perpetrator is long gone.
Mobile robots exist that can find their way around independantly. Let's build some to roam the city, picking up all unattended objects, and throwing them into a built-in container. After a certain run, it should return home to empty the bin, and charge itself up.
Objects should be classified as either garbage or lost objects. Lost objects should have their owner determined, and be returned to their owner. Garbage should be further sorted as recyclable, burnable, or neither. Objects that are neither should be taken to landfill.
The robot should be strong enough to lift a tire, but not strong enough to lift a car. (Taking parked cars is asking for trouble.) The robot must be waterproof in case of puddles or ditches, able to move across grass, sand, and slopes up to 45 degrees, and able to rescue itself from falling into a ditch. If not rescue itself, then somehow call for human rescue. (Yes, I can imagine the robot using a cell-phone-like system to tell me in a synthesized voice that it has fallen, again, into a ditch, at such and such location, and would I please come rescue it. I can further imagine that this would be the twelth time this happened that day.)
Lastly, the robot must not wander into traffic. I doubt it would survive impact with a moving car. It must have some means of telling apart "road" from "sidewalk," and preferring "sidewalk." Bonus points if it can successfully taught to cross the street.