Travel agents in Hue offer cheap buses to and from Dong Ha as part of their DMZ tours. It's also used for connections to Savannakhet in Laos.
It's have mini Bus or Van from Hue(50,000D.) and Danang(100,000D.) all day.
Bus to Savannakhet run by sepon express company departs from Dong Ha on every odd dates 1,3,5th and Back from savannakhet even number day 2,4,6,... (except 31 or 29 Feb no bus leave )cost 180,000 dong. The Bus leave Dong Ha at 08:00 arrive Lao Bao 11.00 to do immigration 1-2 hr. and arrive in Savannakhet at about 16:00 or 17:00. August 2012: Sepon travel no longer do this service despite what their website says. The bus station, about 500m south of the train station (on Le Duan street) have buses that leave from there at 10am to Savannakhet (240,000 dong). You pay the conductor and they try to charge you 350,000dong. Once at the border, Vietnam side is easy but Laos side was hard and bus threatened to take our stuff off the bus because all the foreigners were kept waiting at border control. They eventually went for lunch about a km away so we walked to bus after. It's the same bus all the way.
Also have Van(Someone call mafia bus) to Lao Bao broader cost 35,000-50,000dong run all day
Express VN Train Sai Gon-Hanoi(S1,S2,S3,S4) not stop at Dong Ha station only Local(Slow) train stop.
I found it difficult to find any motorbike rentals along Le Duan, and walking was unreasonable given the long, dusty, hot roads. There are no city buses, so your best option is to take a motorbike taxi to your destination, and have a tour pick you up from your hotel if you plan to do the DMZ.
Ask in some of the hotels along Le Duan or ask at Tam's. they may be ale to help you.
DMZ is an interesting one-day outing from Dong Ha. Tours can be arranged from Hotel 261 (http://dmztours.net/) along Le Duan for around $15-17. This tour will pick you up on the bus coming from Hue, and go to the tunnels, Dakrong bridge, rockpile, and Khe San. Does not include Camp Carol, Con Tien, or food/water, but is a pleasant ride with a spirited guide (propoganda a bit?).
Mine Action Visitor Center, Kid First Village, Dong Ha. Excellent museum on the on going effects of UXO (unexploded ordinance) in the DMZ area. A little difficult to find look for the blue sign on Ly Thuong Kiet Street and follow the dirt road past the Lake. Admission free. Mon-Fri 8am-5pm. www.landmines.org.vn/visitor_center/the_center.html
Dong Ha, Tran Hung Dao street. edit One of the largest markets of the country. People can easily find affordable goods and souvenirs here, most of which are from China and Thailand. Travelers never want to miss this place when they visit Dong Ha city.
Tam's Cafe, 81 Tran Hung Dao Street. Excellent coffee and selection of drinks some good western food and basic Vietnamese dishes. Very helpful owner can arrange tours and help with anything you may need. Most likely place to meet other travelers in town.
Sao Mai Hotel, On the west side of Nguyen Du where it meets 9B. Cheap, clean guesthouse with helpful staff who speak some English. Rooms have ensuite bathrooms, A/C, fan and wifi. Inside parking is available. Singles: 140,000 dong. Doubles: 170,000 dong.
Hoang Lan Hotel, On the east side of Nguyen Du where it meets 9B. Clean rooms have ensuite bathrooms, A/C, fan, wifi and hard beds. Doubles: 200,000 dong. Double with mini-fridge: 250,000 dong.
The Trade Labor Union Guesthouse, provides lodging for 160,000 Dong/Night (15USD if you only have greenbacks).
Hotel Ngoc Anh, 361 Le Duan (south side of town), Nice, new rooms 170/190k. Right across from the train station and just up the road from the local bus station, if that is where you are dropped. Very nice lady who will help with tickets or tours, but speaks little or no English.
Violet Hotel, Ba Trieu, Dong Ha, Vietnam . Excellent budget hotel located near Tran Hun Dao St. Clean rooms with helpful staff, good A/C , hot showers, mini bar, TV. Singles 220,000. Very close to excellent lake side restaurants. Tam's cafe can help with directions.
Thanh Qan Hotel 9b east of Nguyen Du. Avoid this hotel. Insisted on charging a higher rate for foreigners even though there are posted prices on the wall.