I have about 5-10% of my crypto investment spread across some of the major altcoins -- mostly litecoin, but a few others as well. If you're in the mood to gamble, you might want to convert some bitcoin into some cheap-o alts before the next parabolic rise in bitcoin, then convert back into bitcoin after the parabolic rise. But I consider this to be "speculation" (trying to predict what the market will do based on psychology rather than fundamentals) which is less worthy of respect than investing, which is based on one's understanding of market fundamentals.

As for ether, I'll probably buy a little bit, but I plan to reassess when it comes out. I read something recently by Vitalik about bitcoin sidechains in which he said that Ethereum would probably not work as a sidechain, bc it's too different, but he also indicated that Ethereum could work *with* bitcoin and other alts as opposed to being a competitor that might replace bitcoin. As a long term bitcoin investor, I am encouraged by that.