I have a pair of Sanuk flip flops that I wear to the parks, that are also the yoga mat material... love them. Also a pair of Crocs flip flops (not those atrocious, ugly, holed things they sell). I have a pair of Nike LunarGlides I brought last time as well, just to mix it up. They are great running shoes... not as great for walking all day in. I will probably be bringing my new NewBalance Fresh Foam 980s this time around as they are
SUPER comfortable to walk in and I also bought some Tevas sandals that wrap around the foot to replace the Crocs flip flops.
And I've seen several people talk about moleskin... forget that.
Band-Aid Friction Block. THIS is what you need. It is a GODSEND. It is wonderful. You spread it around anywhere you know you'll get a blister and voila... no blister. It will not make your feet slippery or greasy. It's great. The ONE DAY I forgot to apply it, I got several blisters. Then I put the stuff ON the blisters the day after and I was saved from pain... lots and lots of pain from there on out. I can't oversell this stuff. And it's relatively cheap, too. I get it at Walmart for $4 and we don't even use a whole stick while we're there, but we bring two just in case. Buy some, you'll thank me later.