Yup, but equally, one of the forum sponsors is selling a 5m DVI->HDMI cable for £75, which is obscene for what it is. Trouble is, there's currently so little demand for this stuff that prices are still very high.
Hopefully, now more displays are coming with HDMI inputs, when Sky bring out their HDTV system and more people start to want to use the HDMI stuff, switches and cables will come down in price significantly. I can still remember buying my first 2m DVI cable for 40 quid, whereas now you can get them for closer to £4.
The same switch *should* do for the other purpose too (one input into two outputs) - after all, all it does is connect one connector to another, it doesn't care which way the electrons go
You may be able to get away with a simple splitter, but I wouldn't like to guarantee it - there might be termination issues.