Is it possible to somehow connect a monitor, keyboard and mouse to an Android phone and then use it as a lightweight computer (netbook-like)? If it is, what Android version / phone type support it, and how can it be done?
I know that 2 years ago, the guys behind REDFLY presented a proof of concept working with their terminal; but I've heard nothing else about it and a lot has changed with Android over the past 2 years.
Samsung have a dock for the Galaxy Tab which connects it to a pretty much full-size keyboard, and props the screen in a position where it's like a laptop's screen. There are also a number of Android devices that have a video or HDMI out capability to output their screen onto a TV, often needing a special converter cable.
Bluetooth is an option for connecting keyboards, KeyPro (AppBrain Link) (Official Website) andTeksoft Blueinput (AppBrain Link) (Official Website) load drivers onto your phone to let you use Bluetooth HID to connect up many Bluetooth keyboards (trial versions are free to test your device's compatibility, but it looks like if you want to carry on using it you'll have to pay to register to make it work fully). There are other options for loading Bluetooth HID (keyboard) drivers onto your phone if you root it.
Also, see these previous questions regarding connecting peripherals, such as keyboards and mice, to Android devices using Bluetooth.
Bluetooth keyboard with Android?
What else can Bluetooth do?
External Hardware Keyboards
From Android Honeycomb (Android 3.1) upwards certain devices, that have USB Host support built into their hardware, can attach and use normal USB keyboards and mice (with the appropriate USB host micro-USB to USB converter cable). I have occasionally plugged in used a keyboard this way on my Motorola Xoom.
Motorola have just been showing off their 'Atrix' phone which does pretty much what you're after. It's apparently due 'later this year' (source).
Here's a video of the docking features.
Samsung Galaxy S can output to TV using a special Micro USB to HDMI cable: http://www.youtube.com/watch?v=GTQBAx_BDfk
I'm typing this response using a bluetooth keyboard, bluetooth mouse, and external monitor hooked up to my Samsung Galaxy Nexus. It works great and was very simple to set up. No special drivers or apps needed. I'm using a Dell S2409Wb monitor, an old RocketFish Keyboard and an old RocketFish Mouse.
The Asus EEE Pad Transformer is close to what you are after and available now. I like the way it also extendes the battery life. I would wait for something with a bit more power for this purpose though. I have a feeling that using a single core arm processor with 512Mb ram in my case would feel pretty slow as a desktop experience.
Another thing to note is that Android won't support all the keyboard shortcuts that you are used to on a desktop. I hope this changes because for me it is an obvious evolution. Indeed the concept of a personal computing unit like this is something I have been waiting for for 15 years!
Google for ubuntu for android, the video demonstrates how your android phone can be connected to an external monitor and used as fully functional desktop, while still being used as android phone. Great stuff, mind blowing!!
What should I do to be able to use my USB keyboard and mouse with my Android 2.1 tablet?
I like the idea of bluetooth, but my tablet doesn't support bluetooth.
Is there some device similar to touchpad that can be used instead of tapping to screen?
thank you for answer
You cannot use a keyboard and/or mouse with android. This is not supported unless you have android 3.1 or later. That is the first version that supports USB Host Mode.
For "normal" USB devices, if your device does not support them, you will probably need a MicroUSB -> USB adapter, or a MiniUSB -> USB adapter.