@Fred: The minimum duration for an ADSL service would be 2 months I think. There may be a R200 additional service cancellation fee. In your case the Telkom Do Level 1 broadband would probably be the simplest option @R199 per month for 1GB of data. The Do Level 2 would give you ~4GB for R258 per month. The only problem is availability and the installation time. You would need to get your relatives to check directly with Telkom about availability in this area. Installation times vary considerably but if you pushed hard 2~3 weeks would probably be possible - maybe sooner. If you choose the self install option then installation is usually free and ADSL is activated at the exchange and the customer is required to connect and configure the modem/router. Do the relatives currently have a dialup connection? In many cases this may cost even more than one of the cheapest ADSL options as they would need to pay an ISP every month (R75~R150) as well as call charges to Telkom which vary between 17c and 38c per minute unless they have purchased a special after hours Internet call charge option which costs an additional R80~R150 per month. You should be able to install all the necessary ADSL equipment for them so this might be something that the relatives would benefit from after you leave. There are also cheaper ADSL options starting from R139 per month for 1GB but this would involve taking out a 12 month contract but I think that this includes a free router. You shouldn't worry too much about the small ADSL bandwidth allowance as you can purchase additional prepaid bandwidth very easily online or from garages, retail chains etc. once you have activated an ADSL service. The cost would be around R70 per gigabyte but there are cheaper options. Take a look at
www.do.co.za for more details about Telkom's ADSL packages.
If you only want the service for two months then you will need to either supply your own router or ADSL modem. I would imagine that you should be able to purchase a secondhand device off ebay for a few dollars. Otherwise you could purchase a cheap simple modem online over here for ~R200 - routers cost between R250~R750. It would probably be simpler to choose a wireless ADSL modem router combination than to have a separate modem and router. Popular models that are being used over here include Billion, Dlink, Linksys, Netgear etc.
If you will need to use more than a few gigabytes of data then 3G/HSDPA is going to get quite expensive. These are the typical rental rates. You would have to look at either the 500Meg or 1GB monthly rate as the daily rate includes a R2.50 per megabyte charge i.e. ~R2500 per GB in addition to the R20 or R35 daily fee. You would probably need to rent the device at the airport.
STANDARD 384 kps R 20 p/day R 2.50 per MB
3G HSDPA 1.8 mps R 35 p/day R 2.50 per MB
Monthly Rate 3G or HSDPA
384kps/1.8mps R 499 per month including 500 MB free R 2.50 per MB
384kps/1.8mps R 699 per month including 1GB free R 2.50 per MB
http://www.rentafone.net/rates/3Gdatacards.htm
You could also just borrow a suitable cell phone as mentioned above. Most of the recent cell phones can connect via GPRS or EDGE although the performance will not be much better than standard dialup. 3G or HSDPA capable phones are not as common as they tend to be more expensive. Most phones can be connected to the PC via a USB type cable or via Bluetooth. You can also get PCMCIA, ExpressCard or USB type datacards. Each of these devices has a SIM card holder. You can use your airtime to make calls and to purchase data. A 500MB data bundle costs R189, 1GB - R289, 2GB - R389 etc. All of the bundles expire after 30 days. You can either purchase a prepaid airtime voucher (just a code on a till slip) or you can transfer money to a cell phone number via an autoteller machine at a bank. It might be simpler just to visit a cell phone shop and get them to configure the SIM for data, load the credit and purchase the bundle for you if you think this sounds a bit complicated. You will only need to purchase a bundle once unless you consume it too quickly. If you need to purchase a datacard take a look at several of the European ebay sites such as
www.ebay.de,
www.ebay.co.uk etc. to see if you can find a Huawei E220 at a reasonable price. I wouldn't spend more than 50 Euros. If not then look at the older HSDPA PCMCIA datacards. Just make sure that the card is 1.8Mbps capable and not one of the original 384K ones although these should be very cheap by now.
Since bandwidth is very expensive in SA, none of the WiFi hotspots usually provide unlimited access. Depending on your use you will probably find that 500MB or 1GB of data will be more cost effective than purchasing a certain number of minutes of hotspot access.
Dialup access is another possibility but this could work out much more expensive than ADSL or HSDPA if you need to use it during normal office hours as calls cost around 38c per minute i.e. ~R22.80 per hour. You can purchase prepaid ISP access for around R59 for one month's unlimited access (excluding phone charges) from Pick 'n Pay - SA's version of Walmart. If you only need to use the dialup connection at night you can purchase 75 hours worth of access for R80 i.e. total cost would be R59 (ISP) + R80 (dial plan) = R139 i.e. the same as the cheapest 1GB ADSL package which is faster and can be used at any time.