If you don't mind giving up your privacy, the best rock-bottom accommodations in town are the dormitory beds available at the Salisbury YMCA for HK$230 (US$30/£15), followed by those in the YMCA International House for HK$300 (US$39/£19). Otherwise, Hong Kong's cheapest accommodations are at hostels. Hong Kong and its islands and territories have seven youth hostels and they offer the cheapest rates around. However, most are not conveniently located -- indeed, some require a ferry ride and/or a 45-minute hike from the nearest bus stop, as they are located in country parks.
If you don't have a youth hostel card, you can still stay at a youth hostel by paying an extra HK$30 (US$3.90/£1.95) per night. After 6 nights, nonmembers are eligible for member status and subsequently pay overnight charges at members' rates. It's cheaper for the long haul, however, to purchase Youth Hostels Association (YHA) membership for HK$110 (US$14/£7.15), available at any youth hostel. Note that children 4 and under are not allowed at Hong Kong's youth hostels. For more information, contact the Hong Kong Youth Hostels Association (tel. 852/2788 1638; www.yha.org.hk). Bookings can be made through the Internet, and credit cards are accepted.
The most conveniently located youth hostel is the 169-bed Jockey Club Mt. Davis Youth Hostel, on top of Mt. Davis on Hong Kong Island (tel. 852/2817 5715), with great panoramic views. It charges HK$80 (US$10/£5.20) per night for a dormitory bed for those aged 18 and over. There are also a few private rooms, with a double costing HK$260 (US$34/£17). Facilities include a communal kitchen (bring food with you, as no meals are served) and coin-op laundry room. To reach it, take the free hostel shuttle bus, which departs from the Macau Ferry Terminal (MTR: Sheung Wan) seven times daily in the morning and early evening (check the website for specific times). A taxi from Central costs approximately HK$70 (US$9.10/£4.55). The hostel itself is open daily from 7am to 11pm.
Six other youth hostels are on some of the outlying islands and in the New Territories; most charge HK$50 (US$6.50/£3.25) for dormitory beds for those 18 and older. Check-in is from 4pm. There are kitchens and washing facilities, as well as campsites. Since these hostels are not easily accessible, they are recommended only for the adventurous traveler. Of these, the Hong Kong Bank Foundation S.G. Davis Hostel, on Lantau island about a 10-minute walk from the Po Lin Monastery with its giant Buddha (tel. 852/2985 5610), is the easiest to reach from the airport.
