In semester 1 of 1st year, all new TSP students are encouraged to do a group research project for the TSP showcase for 3 credit pts. It's a small project to get students interested in research and give them the confidence to participate in other projects in the future.
There are several research topics in each of the science disciplines usually all centred around one designated theme. Each group has 4-6 1st year TSP students, 1 3rd year TSP student acting as the group leader and 1 academic mentor who is an expert in the subject of the research project. At the end of the project, the group will do a 5 min presentation and submit a written report.
Last year's TSP showcase theme was the Kyoto protocol and climate change. I chose the applied maths topic, which was to model and optimise emissions trading schemes. There were lots of other interesting topics in other science disciplines - for example, studying the feasibility of hydrogen cells in chemistry, the social impact of climate change in psychology, etc. I had a huge amount of fun working with my group and made a lot of friends. Our group leader was fantastic and offered us a lot of support along the way.
The showcase is the only faculty organised TSP project, but you can always create your own projects (which can be used to claim credit pts). All you need to do is find an academic in your area of interest who is happy to supervise you. I'm very interested in the cross-disciplinary application of information technologies, especially in the biomedical domain so at the start of semester 2, I emailed several researcher who work in areas such as medical imaging, bioinformatics and health informatics to discuss ideas for a project. It's amazing how much enthusiasm these researchers showed to take on a 1st year student who has hardly any clue about their field of research. Funnily enough, I ended up doing an astronomy/IT project instead. We applied some very advanced natural language processing techniques to categorise and extract information from astronomy research papers and built a search engine that allows researchers to very easily find useful information.
I've had great experiences with TSP projects. Usually students don't get any research experience until 2nd/3rd year, but TSP students have the privilege of getting involved with expert researchers from pretty much their first week at uni. There is so much more that you can learn from research than any normal uni course - and the team work, communication, self-learning and management skills that you gain from it are invaluable (and not to mention look great in CVs).
As for the workload - of course it requires effort and hard work. What you get out of it is related to what you put in. It's exactly the same to be doing TSP projects in a combined degree or a single degree because you'll be doing the same standard load of 24cp in a semester either way (unless you decide to overload). The difference between a combined and a single degree is basically this - if you're doing a single B Sc degree, then you can choose an elective subject in almost any faculty you want, but if you're doing a combined B Sc/B Com degree (say), then you have to use that elective to do a commerce subject. That's why a combined degree is shorter than two single degrees done separately. The workload is essentially the same.
TSP projects can be done on top of your standard load of 24cp if, for example, there are some subjects which you must do as prerequisites for your major. Alternatively you can do it in place of the 6cp elective which you get in a single degree. Usually projects can't be used to substitute prerequisite subjects, but there are cases where you can get special permission to do that. For example, a friend of mine who did the chemistry Olympiad was allowed to do a research project instead of 1st year chemistry. The showcase is, in my opinion, the easiest and requires the least amount of effort in comparison to all the other things that you can because it's managed very well by the faculty and you will have a lot of support from your group leader and academic mentor. Definitely give it a go and have a small taste of TSP and research if you get the chance.
There's a lot to the TSP apart from projects. Some schools allow TSP students to enrol in 2nd/3rd year subjects in their 1st year (the school of maths and the school of IT have a bunch of them). For example, I got to do a 3rd year maths subject called Logic and Foundations in semester 1 of 1st year. Also, you can mix and match or even create your own subjects - one of my friends was overloading with 33cp and didn't have time for long labs or to write tedious lab reports for Human Biology so got permission to do only the theory component of Human Biology for 3cp.
On the other hand, there are also lots of TSP students who have never ever done anything related to the TSP. But if you want to do something, then you get a LOT of freedom from the faculty to manage your own studies.