Soda is right…horizon is way off…and it really shouldn’t be. Is best to try and keep it level if possible. It’s easy enough to rectify in an image editing program. Picasa has a handy little straighten tool which I like. I noticed the same thing in your Perth shot as well.
To be honest..it’s something I wouldn’t have noticed myself probably, until I started browsing sites like this one.
There are plenty of tips on basic composition dotted around this site that will help with this kind of thing.