WEP cryptography is not very secure at all. A recent paper from cryptography analysts called the encryption algorithm “kindergarten cryptography”. Actually, software exists that exploits a huge security hole in the encryption standard. This software listens to the encrypted network traffic, analyzes it, and after only a few hours it reveals the password to enter the network in clear text. The more traffic on the network, the easier it is to find out the password.
If you are truly concerned about your security, do not use WEP. If you are just setting up a two-computer home network, well, then I guess WEP should do.
There are many alternatives to WEP encryption. You could only use SSH to communicate over the network. SSH is a program suite that encrypts data with its own algorithm, which is very secure. Another option is to use PPTP, the Point-to-Point-Tunneling protocol. However, even PPTP seems to be a bit leaky concerning encryption security. And finally, you could set up an IPSec tunnel for your encrypted connections. As of yet, this encryption seems to be very safe and flexible.