I clean my Remington 1100 semi-auto pretty regularly or I get cycling problems, mainly failure to fully eject a shell (stove-piping the spent shell). This is particularly bad with light target loads. With the #4 Winchester Super X I shoot for actual game I almost never have that problem. I also carry spare O-rings for it, since that's its weak link.
The rest of my guns I clean once a year. But lately on camping/hunting trips I've started carrying a small cleaning kit with a break-down cleaning rod I picked up on sale from Murdoch's on sale one day. I had a bad fall on a steep descent that gave way under me this past hunting season and I fouled my rifle barrel. It was really cold, and I got snow and mud frozen onto and a little bit into the barrel. It wasn't much, but because it froze in there, I couldn't get it out and it wouldn't have been safe to shoot. I like the peace of mind of having a rod, some patches, and brushes with me at all times as well as a small can of One Shot and some swabs.
For cleaning I have all the usual gear: rods, patches, jags, etc. But I have to say the easiest thing I've ever used is a Bore Snake. Those things are magic. The only bad thing IMO is with the "standard" (brushes/patches) option, you're throwing out most of the junk with the patches. With a bore snake it tends to accumulate, so I keep mind in a ziploc.