Robots, also known as 'Droids' are common throughout the galaxy. So common they are often overlooked. But using them the Seperatist armies caused havoc during the Clone Wars. The line between sentient and robot can be thin, as a robot who has not received a memory wipe can develop it's own unique personality.
There are three main events in history effecting Droids on a massive scale.
Helpful Robots
Astromechs have a wide variety of functions. The most common is assistance in starship navigation and repairs. The most popular
brand is the R series, with the R2 unit being the most popular version. It's adaptability and customization options make it even more popular than later models in the same line. The tools are concealed within compartments in the body,
in this R2 unit, they include a holo recorder and emitter, jets for manuevers on the hull while in space, a computer data probe and an arc welder.
Power Droids These basic, box droids have two feet and one prime function. Power everything that needs it, electronics, machinery and transports. This is their only real function and they are not versatile.
image source: Droidworld, Photobucket
Pit Droids These strong little droids were designed for race maintenance, especially pod racing. They also can repair swoops or other vehicles. They are not very smart however and can be a hazard when malfunctioning. They are very short in height and fold down when deactivated.
image source: dkosa, Photobucket
ASP Droids are the heavy laborers. They are commonly used in spaceports
for odd jobs requiring heavy lifting.
Medical Droids These are medical professionals, programmed with treating injury and illness
in organic beings. Some are specialists, others more general in scope. They can make excellent surgeons.
image source: mentat 9777 Photobucket
Protocol Droids specialize in interaction between human and machine, usually other robots although they also interpret for cyborg and computers.
They may also translate between species that don't share an ability to speak galactic 'basic'.
Dangerous Robots
Buzz Droids are fired as missiles at enemy craft. Upon impact or near impact, they burst open to reveal the droid.
The droid proceeds to attack the vessel, damaging any systems, including life support, weapons, and engines.
Magna Guards were tougher than average combat droids and more specialized than assassin droids. They were programmed and designed with killing Jedi in mind during the Clone Wars. They were the personal bodyguard of
General Grievous, the cyborg leading the Confederacies Fleets.
Assassin Droids are highly dangerous programmed assassins who will kill any target an anyone who gets in the way. Due to the lack of the usual safeguards against harming an organic being, these droids can be extra dangerous when malfunctioning.
image source: cantina00 Photobucket
Battle Droids usually are controlled from a central location. En masse they can form a formidable army.
However, they are not quick to adapt to new situations and have no shields, so their primary advantage is in numbers. They usually fold up when not in action, allowing for more to fit in the transport vehicles. Weapons are standard blaster rifles.
Super Battle Droids were developed to compensate for the weakness of the original battle droid.
The heads are centered in the torso to prevent damage, they have heavier firepower which is built into the arms and heavier armor. They also have more ability to think independent of the central control.

Droidekas were designed by the Colecoids, and therefore retains it is based on their own anatomy. It rolls into battle in a wheel shape, unfolding into tripod legs with arms ending in blasters. It usually has shields, making in particularly tough in combat.
On Earth, Droids have yet to exhibit the highly adaptive emotional functions of R2-D2 or C3PO. However, artificial intelligence is a work in constant progress. When the original Star Wars trilogy
was made, there were two R2s. One with an actor inside, one a real robot. The real robot hardly worked. Now, you can find one in stores that carry collectibles. It will bring you a drink, play games, work as a door alarm and respond to familiar names.
Honda has created a real functional robot called Asimo with bipedal motion and facial features.
Toyota has also been working on robots, some play musical instruments.
Sony's Aibo, imitates a dog.
Kismet is merely a robot 'head' but is programmed to respond to human emotions based on their facial responses.
In the utility department, you can get a Roomba, a small disc shaped robot that
vacuums the floor without any assistance from you outside using the 'on' switch.