Thank you all for your wonderful posts.
I'm in process myself to built a make-shift darkroom in my bathroom, and your posts have inspired me very much. I live in a two-bedroom apartment with only a small bathroom, and so far I have placed the enlarger on the toilet and I could manage to have four 8x10" trays on the floor under the shower.
I'm still contemplating how to improve this, as it is not the most comfortable to work in, and your input has led me to believe that working in layers is the best approach. By working in layers I mean to put up some sort of shelf system on wheels where the top shelf will house my enlarger and then maybe four shelves under each other with different trays, e.g. developer, stop, fix and water bath. The Ikea antonius system seems obvious for this, although I really want something that I can collapse and store away as my space in generally is limited.