April 2010 Cumulative Update released!

This cumulative update includes a fix for a possible memory leak (which may cause the application pool to recycle the AppDomain because many instances of the SPHttpApplication reach memory limits), so it's strongly recommended that everyone applies this fix on their SharePoint 2007 environments.

WSS: http://support.microsoft.com/kb/981043
MOSS: http://support.microsoft.com/kb/981042

Download links:
WSS: http://support.microsoft.com/hotfix/KBHotfix.aspx?kbnum=981043&kbln=en-us
MOSS: http://support.microsoft.com/hotfix/KBHotfix.aspx?kbnum=981042&kbln=en-us

- WSS (& MOSS) with Service Pack 2
- all Language Packs for WSS (& MOSS) should also have their respective Service Pack 2 applied