Yangshuo - About 1.5 hours by bus from Guilin is the friendly and picturesque town of Yangshuo. This used to be a popular backpackers town, but now is full of Chinese tourists. It is situated in a beautiful karst landscape. The full day boat trip along the Li River will finish in this town. Getting there by taxi or bus and is also an option.
Xingping - This town will probably become the next backpacker place, as Yangshuo becomes too commercial for backpacking types. It is a very peaceful, old town located on the Li River's most beautiful landscape, half way between Yangshuo and Guilin.
Longsheng- An area near Guilin with hills covered with terraced rice fields. There are many organised tours from Guilin, many of which will allow you to visit the nearby ethnic Zhuang minority villages. June and September are good times to visit when fields are flooded.
Vietnam - There is a new sleeper over night bus route from Guilin to Hanoi (http://blog.sina.com.cn/s...). It costs ¥390 leaving in the evening every day and arriving Hanoi next day. Or catch the afternoon train to Nanning 5hrs, stay overnight in a cheap station hotel and get the early morning bus in Langdong bus station to Hanoi, arriving about 3PM depending on traffic.
As with any international transfer, check Vietnamese visa requirements for your country.