Gets rid of the recently viewed items on the tab. Always shows the most recent list view.
It's good, but it does remove all of the links on the standard Lead screen such as Mass Email, Reports etc.
Mass Transfer - Go to Setup | Administer | Data Management | Mass Transfer Records
Mass Delete - Go to Setup | Administer | Data Management | Mass Transfer Records
Organisations Merge https://ap1.salesforce.com/merge/accmergewizard.jsp
Mass Add Contacts to Campaign https://ap1.salesforce.com/ui/campaign/MassAddCampaignMembersWizard?macmw_type=Contact&macmw_mode=Add&wizardRetUrl=%2F003%2Fo