Salesforce sObject ID Prefix

001 - Account

02Z - AccountContactRole
00r - AccountShare
01M - AccountTeamMember
04m - AdditionalNumber
01p - ApexClass
099 - ApexComponent
066 - ApexPage
01q - ApexTrigger
806 - Approval
02i - Asset
707 - AsyncApexJob
00P - Attachment
016 - BrandTemplate
019 - BusinessProcess
04v - CallCenter
701 - Campaign
00v - CampaignMember
01Y - CampaignMemberStatus
08s - CampaignShare
500 - Case
00a - CaseComment
03j - CaseContactRole
01n - CaseShare
010 - CaseSolution
02o - CategoryData
02n - CategoryNode
09a - Community
003 - Contact
03s - ContactShare
800 - Contract
02a - ContractContactRole
015 - Document
05X - DocumentAttachmentMap
02s - EmailMessage
093 - EmailServicesAddress
091 - EmailServicesFunction
018 - EmailStatus
00X - EmailTemplate
00U - Event
020 - EventAttendee
022 - FiscalYearSettings
00l - Folder
608 - ForecastShare
00G - Group
011 - GroupMember
0C0 - Holiday
087 - Idea
00a - IdeaComment
00Q - Lead
01o - LeadShare
029 - LineitemOverride
01H - MailmergeTemplate
002 - Note
006 - Opportunity
00J - OpportunityCompetitor
00K - OpportunityContactRole
00k - OpportunityLineItem
028 - OpportunityOverride
00t - OpportunityShare
00q - OpportunityTeamMember
00D - Organization
0D2 - OrgWideEmailAddress
00I - Partner
026 - Period
01s - Pricebook2
01u - PricebookEntry
04g - ProcessInstance
04h - ProcessInstanceStep
04i - ProcessInstanceWorkitem
01t - Product2
00e - Profile
021 - QuantityForecast
04X - QuantityForecastHistory
03g - QueueSobject
012 - RecordType
027 - RevenueForecast
04W - RevenueForecastHistory
01N - Scontrol
035 - SelfServiceUser
0DM - Site
501 - Solution
081 - StaticResource
0t0 - TagDefinition
00T - Task
005 - User
01D - UserAccountTeamMember
100 - UserLicense
03u - UserPreference
00E - UserRole
00p - UserTeamMember
083 - Vote
00b - WebLink

http://www.salesforcefast.com/2012/02/salesforce-standard-object-record-id.html