With every client I work for, I start to look for interesting subjects that client is involved with.
As a software testconsultant I had a lot of different clients the last six years, so you can imagine the diversity of areas I've seen.
For me one of the most interesting areas is the financial services area. Not because of the arithmetics (still not my cup of tea), but because of the innovative way these services try to adapt to the changing financial environment.
I started to see this in the beginning of internet banking and at the moment I see financial services woven into social networks like Hyves, web 2.0 as you may call it.
Very interesting for a tester, because these financial services and social networks will form an 'in silico' ecosystem (I'm still a biologist :-)), and like a living ecosystem very intricate and therefore very susceptible to errors.
To minimize this error-proneness (Open) Standards (like XBRL) were developed to make interoperability between the systems possible and to prevent also vendor-lockin.
But even standardization does not fully minimize the errors, because using standardization in design and development is still a human job, resulting in possible errors.
And what I've seen in online financial services, things can get very messy if an XML-tag of a webservice is not well tagged.
Standardization increases interoperability, but does not mean errors can't be made.