For $522 (or less in winter) you can get a 30-day unlimited Greyhound pass usable anywhere in the US and Canada. A 15-day pass is around $450. That's a bit more expensive than a single round-trip flight, but you can visit several places along the way and you don't have to set your itinerary a month in advance. That's good if you're visiting several people in different towns in the same region. Trying to do that flying is impossible: you'd spend something like 2000. On the bus you can change your itinerary at any time.
It takes three days to go from the west coast to the east coast, two days from the west coast to Chicago, and 16 hours from Chicago to New York. Likewise it's two days from Seattle to Dallas. The bus travels 24 hours, changing drivers every 8-10 hours. Three times a day there's a meal stop at McDonald's or a small-town restaurant. Every couple hours it stops at a mini-mart for a smoke break, bathrooms, and snacks. There's also an onboard toilet (a low-tech built-in porta-potty).
The best part about the bus besides having time to think and read and watch the scenery, is the people you meet. Young people on college break or visiting or moving somewhere, people visiting their families in small towns, truckers coming home from a job, army boys on their way to boot camp, international travellers, parents with children -- people you'd never see otherwise. One year the bus stopped at Snoqualmie Pass and this guy from South Africa was so excited, he'd never seen snow before. So he threw his first snowball at his girlfriend. The riders are generally more working-class than on a plane or train: people who just want to get from point A to B cheaply.
There's a lot you have to put up with, however. At random on some trips you'll find loud obnoxious people, a seat you can't sleep in, a full or almost-full bus, late buses, breakdowns, etc. Greyhound doesn't take reservations so the first in line gets the best seat. And if you're transferring, the line may already be long by the time you arrive. Supposedly if a bus is full (55 people) they'll put a second one on, but sometimes you get bumped and have to wait four hours till the next one. A few express routes always have two buses.
The secret to handling these problems is just to expect them, then you'll be calm when everybody else is agitated or freaking out. Bring a pillow, something to read or listen to, earplugs, and enough food and batteries. Some of the mini-marts have nothing but junk food; plan ahead in case the next one is horrible. E.g., if you find wrapp sandwiches, get one for now and one for later. And bring one meal and your first day's snacks with you: city supermarkets are much cheaper than mini-marts and have a wider selection.
The most likely bets at mini-marts for a high-protein low-junk diet are orange juice, milk, sandwiches, beef jerkey. Splurge on a hamburger or doughnut if you haven't had one for a while, but not for every meal. Check the McDonald's nutrition chart, a Big Mac has 560 calories! Surprisingly, a 16-oz shake has 550, and a large fries has 570. Most people have a resting daily requirement of 1500-1950 calories. No wonder people in America are so fat: a "complete" McDonald's meal fills an entire day's caloric requirement but of course it doesn't keep you full for 24 hours. So have a Big Mac one meal, a salad the next, and you'll probably feel better. Try making every other meal vegetarian, or get a salad with chicken. Add an apple to keep hunger pangs away, and a chocolate bar so you don't feel deprived and irritable. My first cross-country trip I spent $35/day on food and gained five pounds. My last one I spent $15, lost five pounds, and skipped the mini-marts half the time because I wasn't hungry.
Greyhound has been cutting back on service so I worry about its long-term viability. They've withdrawn from smaller routes (e.g., Billings - Minneapolis) and are squeezing everybody into the Denver - St Louis corridor for east-west trips. Unfortunately the local station masters don't realize everybody in the country has to go through there so they should plan for multiple buses every day. Instead they're overoptimistic and penny-pinching, until it's obvious 15 minutes before departure that not everybody will fit. Then it's a crisis and passengers are pissed. I can't count how many times I've heard people say this is their first bus trip and they're never going to do it again. Surely the cost of a second bus isn't that much compared to the company's reputation? A happy rider might buy ten more tickets in their lifetime: that's a fifth of the bus's capacity right there.
When Greyhound withdraws from a route, a regional bus company steps in. So there's still service, but maybe only once a day rather than 2-3 times. I assumed the regional companies used Greyhound reject buses, but actually they're higher quality that Greyhound, at least on the two I've been. Most of the regional companies have the word "Trailways" in their name. I asked an agent why, and she said Trailways is the scheduling/ticketing system all the companies share. So Greyhound is a Trailways company; they just don't have it in their name for marketing reasons, so that it looks like they're the big dog (excuse the pun) doing national reservations for everybody else, when actually they're just using the common ticketing system.
Overall I find travelling in the western US less stressful than the east. It's 10-20 hours between major cities and the bus usually keeps travelling in a straight line, so you don't have to transfer every 4-8 hours like you often do back east. There's less bullshit on the less-travelled routes. A driver once told me she preferred the northern route (I-90) over the west coast route (I-5): "the snow keeps people honest".
The best way to sleep, I've found, is to lean your head on a pillow against the window.
Sluggo is Mike Orr, a helluva friendly guy in Seattle. Email me if you have feedback.