Java

When facing problems regarding memory consumption of a Java application, the JDK contains a number of useful tools to help you understand what is going on. You can get a list of the tools on this page.
One of these tools is "jmap". Jmap will let you now (among other things) know what objects are using your precious memory.

Cool!
...
except that when you try to use jmap on Ubuntu 11.04 with a Sun JVM 6, you will get this error message:

Attaching to process ID 12450, please wait...

I used to profile my Java applications with the TPTP Eclipse plugin. It was admittedly a nightmare to install, but once you had it running, it was a fairly efficient tool. Alas, to my dismay, I realized that TPTP is no more. The project was dropped from the latest Eclipse release train (Indigo). And of course, one week after the new Eclipse release, I have a need to profile a remote server.