But now maybe the kids have spring break, or you've got a bit of time coming off, and you're thinking maybe now that the average temperatures are above freezing, you'd like to use your bike to take a bit of vacation. But what, if anything, do you need to change to make your daily ride into something capable of overnight trips?
The answer, of course, depends on your current commuter bike setup, and what kind of trip you want to do. If you're currently riding a skinny-tire fixie and want to take a week-long camping trip, it's going to be difficult. On the other hand, if you're got a bike with multiple bags and baskets for hauling groceries, or a trailer (for the kids, for cargo or for musical instruments), you can pack up and go without much fuss at all (there are, of course, bikes designed specifically for loaded touring, which are ideal for this, and actually make pretty good bikes for long-distance commuting, but they can be quite an investment if you're not planning on using them often).
On the other hand, if you're planning on a short camping trip (what Grant Petersen calls a "Sub-24-Hour-Overnight") or plan to sleep indoors at a friend's or Bed and Breakfast, you just need a bike that's comfortable and a way to carry a minimum of basic gear. A hybrid or mountain bike with a rear rack to lash a duffel bag of clothes will work just fine (I advise against backpacks or messenger bags for overnights, as they get uncomfortable on longer trips, though some people use them). Baskets suitable for carrying groceries will carry clothes, snacks and lightweight camping gear just as well (put everything in large ziploc bags or trash bags to waterproof it). If the weather is nice and you want to camp, a basic nylon tarp can be enough shelter, and inexpensive fleece sleeping bags are more than adequate when combined with a cheap foam sleeping pad. Cooler or wet weather is going to demand better, more expensive gear, at least if you're interested in being at all comfortable. Of course, getting dry clothes and a hot shower at the end of a rainy trip is argument enough in favor of the "ride to a hotel" route.
There's no argument that being able to camp out can save you a lot of money on a longer trip, and if you're planning on doing it a several times a year, or for an extended period, it's worth investing in a loaded touring setup, but if you're trying bike touring for the first time, or only go for weekend getaways, the money you spend on a touring bike, decent bags and lightweight camping gear will set you back far more than a night at all but the fanciest B&B. Of course, there's nothing to say you have to pick one over the other, you can mix weeklong camping trips in with the occasional overnight to a nice riverside inn, or on a long camping tour, decide to spring for a motel on rainy nights.
I've normally used my regular commuter or road bike for extended trips, and went the "Bed & Breakfast" route. I use a big saddlebag and a handlebar bag (I keep my wallet, phone and the like in the handlebar bag, so if I want to stop and lock up the bike somewhere for lunch or sightseeing, I can just unclip it and carry it with me. If someone wants to rifle through my dirty laundry in the saddlebag, that's their concern. I've also done large group rides where our gear was carried in a support van, but I find I enjoy the semi-independent style of carrying just enough of my own gear to get through the weekend.
I'm planning a trip next week with my middle-school-age daughter, who will be on spring break. We'll be taking our bikes down a canal path to an inexpensive B&B, and I'll post pictures of our touring rig.