Currently I am learning Smalltalk. I do this because I want to learn as much as I can in one week about a new programming language in order to improve my skills. Next week I will try something else.
So far I am able to read Smalltalk code but I have a very limited experience in writing. Can you recommend me any small size project that will help me understand better this language in a short time period?
Look into a book Squeak by Example, there are many examples to work on and practice. After a while you'll be very well prepared for some real, yet mini project.
I think you need only few days for a book with examples, so this is well spend time even if you have just one week.
Anything not too trivial goes well. If you plan going on squeak, I'd propose you to write a card game, lottery or something else such.
It'd be more useful for you to find out some example code though. What prevents you from writing C in smalltalk?
You can have a look at Programming whith robots.
It depends on the cognitive abillities and the availabel time for learning, but I think the BotsInc material can be mastered in one week. There is a Free book version for download available. And for small real world projects there is NXTalk announced for early this year.
Just do whatever you'd do in the language you already know. Taking a small task like writing a simple TODO list or even simple blog will undoubtedly improve your Smalltalk skills.
And remember to be easy on yourself. Expecting too much too soon can be intimidating.
I really, really like The Laser Game Tutorial
Tutorial: Squeak Development Example for Squeak 3.9
A.K.A. "The Laser Game Tutorial" This excellent tutorial by Stephan Wessels will guide you through installing Squeak, to creating a fun game using the Morphic graphics system, all > while observing solid object-oriented design principles
It is divided in 6 Sessions so 1 each day although I must say each session has taken me two hours or so.
Perfect for your objectives.
Apart from the The Laser Game Tutorial. (that I recommended in my previous answer)
There is the "The Bowling Game"
Article: Discovering Better Code Series
A.K.A. "The Bowling Example" A guided tour through the mind of a Smalltalker: How to build a business model from the ground up, factoring it along the way. If you don't understand how Smalltalkers think or why they think that way, you need to read this series.
The really nice thing about this project is that it is like being the pair-programmer of a great developer.
The author Ron Jeffries is one of tho founders of Extreme Programming and a book author.
So it is a really good resource. I wish more tutorials where written like this.
I really enjoyed Ted Bracht's Dolphin Smalltalk Tutorial:
http://www.amazon.co.uk/Dolphin-SmallTalk-Tutorial-Ted-Bracht/dp/0201737930
It takes you set-by-step through a GUI-based windows application. It's a pretty good tutorial.