For a year or two now I have been using a nice systray utility from dbmotive that has served me very well in managing the variety of Oracle Homes that I always seem to have on my machine. It is called Oracle Locator Express – it looks like it used to be called Oracle Home Selector or something like that or perhaps is a replacement for it.
It runs in your systray and looks something like this
As you can see I have Oracle homes for Oracle 11g, 10g, XE, and Instant Client (not sure what the Instant Client thing is though?). For my day to day development work I use the 10g client to connect to the various Oracle databases that I use. Occasionally when I have something that I want to try out or test (like the Linq to Oracle prototype that is out there) I will switch over to the XE version. This makes it very convenient and hassle free compared to what I have had to do in the past. You just right click on the icon in the systray and up pops the menu above. You select the Oracle Home you want to be active and away you go. You have to restart any applications that you want to use this new Oracle Home. For example I would need to restart Visual Studio so that it picks up the new path to the Oracle Home same goes for any SQL apps you might use like TOAD or PL/SQL Developer.