Viewing large files on Linux/Solaris

Log files of J2EE applications can become very big. In our application, the log files were of the size ~ 700 MB to 1GB.
To search such big files for information the following unix commands can be used:
- less fileName.txt
To search a string in the forward direction
- /searchString
To move to the next search
- n
To search backwards
- ?searchString