Subject: Benelux and Switzerland
I've made a trip thru Switzerland last year.
>From Interlaken the one thing to see is Moench, Eiger, Jungfrau (the three big mountains). For seeing the Jungfrau (which ended up impossible because of the weather) an old lady recommended not to travel on the Jungfraujoch (which is very expensive) but to travel on the smaller mountains in front of the Jungfrau (several possibilities) because then you can see the Jungfrau much better.

I'd say to travel to Zermatt from Interlaken is too far. What about extending your trip a bit? I've made my way from Interlaken first to Bern (nice town) then to the area around Fribourg (french Switzerland) and then the valley of the Rhone up to Zermatt (where I stayed in a hotel). It takes quite a time travelling in Switzerland - there are such a mass of mountains in the way. :-)

I'd second the idea with Bruges (we call it Bruegge) - a nice town