Ukuleles are definitely a 'real' instrument. I hate it when people say that they are just a toy...
I do play one, and have for five years.
I do not know why the uke is tuned so strangely, but it just makes it even cooler!
And last but not least, yes, you should get one. Ukuleles are the most amazing instruments I have come across so far, and the sound in so unique. I am from Hawaii, so ukuleles are part of our culture in a way.
-Melissa