On Linux a nice small but highly effective tool I use to work with SVN is RapidSVN. The program is pretty small but highly effective for commit, checkout, merge, and log info.

RapidSVN works on Windows, Linux and MacOS X.

From their site, the list of features include:

• Simple -easy to use for SVN features;
• Efficient – simple for beginners but flexible enough for those experienced with Subversion;
• Portable – runs on several platforms on which wxWidgets can run (Linux, Windows, Mac OS/X, Solaris, etc).
• Fast – written in C++
• Multilingual – translated to many languages: German, French, Italian, Portuguese, Russian, Ukrainian, Simplified Chinese, Japanese