Exactly, cheapest, fastest, and with real people. That's all I want to talk about "Meet up" function on Couchsurfing, which is one way to explore the world.

Leaving Facebook is awesome. Since I realized that Facebook is not the place for my words, I started seeking out for new energy sources, I mean mostly positive vibe, cause I found that Facebook does not influence me in a good way.
So the journey began.
Back to 2013, when reading some travel blog posts, most of them from Huyen Chip — the famous young Vietnamese author, I encountered the word “Couchsurfing”. At that time, I was only a freshman, with little English lexical resource; I can barely kick off a conversation with foreigners, let alone talk to them around the clock. Also, my only means of transportation was by bus, and it took me way too much time to attend weekly meet up. Another excuse and I had delayed it for nearly six years. 
When coming back, I had a change of heart and had logged in CS nearly every day. In the first place, as I didn't want to make the first move, all I have done are completing my profile, adding some pictures and favorite spots around Hanoi. Below is one relatively complete profile:
Thanks to my diligence on my profile, within a few days afterward I have not one but three people asking me about some famous spots and invite me to hang out with them. Well, it's just a little number, but for a CS novice like me, it feels like magic. 
Even though  I can not offer them a room in my house, believe me, they love to have some local buddies to show them around, and it costs you virtually zero to practice speaking with foreigners. No matter what language you want to learn. For example, if you are learning Mandarin, you could use the searching filter to choose the nationality, the gender, the age and of course, the language they are using. Check it out:
 Sooner or later you will realize, some of them are polyglots, who can speak several languages; some of them are world travelers, who can easily handle a motorcycle. You would be pumped to cross paths with plenty of occupations, nationalities, religions, and personalities. Sounds great, huh?
But remember, some of them are also Casanova, even worse because I don't have a chance to experience as a host/surfer, living with them for days. But you must be careful while reading, not skimming, their reviews, don't let some touched-up photos or hundreds of reviews blur your eyes. You may encounter some guys who have only compliments on reviews; the overall rate, however, is "would not stay with ... again". Perhaps the reviewer is trying to be polite. Just like this:

The information shown above is just my quick note about Couchsurfing. If you want to learn using it adequately, here are some blog posts that would help you out: