I'd hide on the roof with a cricket bat and some supplies. I reckon the Zombies can't get up, and I can easily roof-hop (semidetached, after all) up to some local shops, or to the top of the street. My area is surrounded in farms, walking areas, cycling paths and a park, so I'm hopefully protected by a sea of unpopulated green, what with Zombies having short attention spans and desperate hunger and all.
I had a dream last night where I was IN a L4D-like scenario. At one point I was guarding a fort, and I discoverd that the zombies were being led by clones of me and other guys from school.
Then I was in a forest, and I was attacked by three spitters. I bumped into some other Zombies, and discovered that they were sentient and could talk. They were bumpkins, however, and stupidly mistook me for another zombie. They befriended me and invited me to come with them. They took me to a zombie Glastonbury/Woodstock. I realised that smarter zombies would call me out, and I fled.
It was WEIRD