Status 500 internal server error "no such file to load sqlit

Please help me am using ubantu as operating system and geting following
error

[2010-06-12 19:00:14] INFO WEBrick 1.3.1
[2010-06-12 19:00:14] INFO ruby 1.8.7 (2008-08-11) [i486-linux]
[2010-06-12 19:00:19] INFO WEBrick::HTTPServer#start: pid=18978
port=3000
/!\ FAILSAFE /!\ Sat Jun 12 19:00:35 +0530 2010
Status: 500 Internal Server Error
no such file to load – sqlite3
/usr/local/lib/site_ruby/1.8/rubygems/custom_require.rb:31:in
gem_original_require' /usr/local/lib/site_ruby/1.8/rubygems/custom_require.rb:31:inrequire’
/usr/lib/ruby/gems/1.8/gems/activesupport-2.3.8/lib/active_support/dependencies.rb:156:in
require' /usr/lib/ruby/gems/1.8/gems/activesupport-2.3.8/lib/active_support/dependencies.rb:521:innew_constants_in’
/usr/lib/ruby/gems/1.8/gems/activesupport-2.3.8/lib/active_support/dependencies.rb:156:in
require' /usr/lib/ruby/gems/1.8/gems/activesupport-2.3.8/lib/active_support/core_ext/kernel/requires.rb:7:inrequire_library_or_gem’
/usr/lib/ruby/gems/1.8/gems/activesupport-2.3.8/lib/active_support/core_ext/kernel/reporting.rb:11:in
silence_warnings' /usr/lib/ruby/gems/1.8/gems/activesupport-2.3.8/lib/active_support/core_ext/kernel/requires.rb:5:inrequire_library_or_gem’
/usr/lib/ruby/gems/1.8/gems/activerecord-2.3.8/lib/active_record/connection_adapters/sqlite3_adapter.rb:10:in
sqlite3_connection' /usr/lib/ruby/gems/1.8/gems/activerecord-2.3.8/lib/active_record/connection_adapters/abstract/connection_pool.rb:223:insend’
/usr/lib/ruby/gems/1.8/gems/activerecord-2.3.8/lib/active_record/connection_adapters/abstract/connection_pool.rb:223:in
new_connection' /usr/lib/ruby/gems/1.8/gems/activerecord-2.3.8/lib/active_record/connection_adapters/abstract/connection_pool.rb:245:incheckout_new_connection’
/usr/lib/ruby/gems/1.8/gems/activerecord-2.3.8/lib/active_record/connection_adapters/abstract/connection_pool.rb:188:in
checkout' /usr/lib/ruby/gems/1.8/gems/activerecord-2.3.8/lib/active_record/connection_adapters/abstract/connection_pool.rb:184:inloop’
/usr/lib/ruby/gems/1.8/gems/activerecord-2.3.8/lib/active_record/connection_adapters/abstract/connection_pool.rb:184:in
checkout' /usr/lib/ruby/1.8/monitor.rb:242:insynchronize’
/usr/lib/ruby/gems/1.8/gems/activerecord-2.3.8/lib/active_record/connection_adapters/abstract/connection_pool.rb:183:in
checkout' /usr/lib/ruby/gems/1.8/gems/activerecord-2.3.8/lib/active_record/connection_adapters/abstract/connection_pool.rb:98:inconnection’
/usr/lib/ruby/gems/1.8/gems/activerecord-2.3.8/lib/active_record/connection_adapters/abstract/connection_pool.rb:326:in
retrieve_connection' /usr/lib/ruby/gems/1.8/gems/activerecord-2.3.8/lib/active_record/connection_adapters/abstract/connection_specification.rb:123:inretrieve_connection’
/usr/lib/ruby/gems/1.8/gems/activerecord-2.3.8/lib/active_record/connection_adapters/abstract/connection_specification.rb:115:in
connection' /usr/lib/ruby/gems/1.8/gems/activerecord-2.3.8/lib/active_record/query_cache.rb:9:incache’
/usr/lib/ruby/gems/1.8/gems/activerecord-2.3.8/lib/active_record/query_cache.rb:28:in
call' /usr/lib/ruby/gems/1.8/gems/activerecord-2.3.8/lib/active_record/connection_adapters/abstract/connection_pool.rb:361:incall’
/usr/lib/ruby/gems/1.8/gems/actionpack-2.3.8/lib/action_controller/string_coercion.rb:25:in
call' /usr/lib/ruby/gems/1.8/gems/rack-1.1.0/lib/rack/head.rb:9:incall’
/usr/lib/ruby/gems/1.8/gems/rack-1.1.0/lib/rack/methodoverride.rb:24:in
call' /usr/lib/ruby/gems/1.8/gems/actionpack-2.3.8/lib/action_controller/params_parser.rb:15:incall’
/usr/lib/ruby/gems/1.8/gems/actionpack-2.3.8/lib/action_controller/session/cookie_store.rb:99:in
call' /usr/lib/ruby/gems/1.8/gems/actionpack-2.3.8/lib/action_controller/failsafe.rb:26:incall’
/usr/lib/ruby/gems/1.8/gems/rack-1.1.0/lib/rack/lock.rb:11:in call' /usr/lib/ruby/gems/1.8/gems/rack-1.1.0/lib/rack/lock.rb:11:insynchronize’
/usr/lib/ruby/gems/1.8/gems/rack-1.1.0/lib/rack/lock.rb:11:in call' /usr/lib/ruby/gems/1.8/gems/actionpack-2.3.8/lib/action_controller/dispatcher.rb:114:incall’
/usr/lib/ruby/gems/1.8/gems/actionpack-2.3.8/lib/action_controller/reloader.rb:34:in
run' /usr/lib/ruby/gems/1.8/gems/actionpack-2.3.8/lib/action_controller/dispatcher.rb:108:incall’
/usr/lib/ruby/gems/1.8/gems/rails-2.3.8/lib/rails/rack/static.rb:31:in
call' /usr/lib/ruby/gems/1.8/gems/rack-1.1.0/lib/rack/urlmap.rb:47:incall’
/usr/lib/ruby/gems/1.8/gems/rack-1.1.0/lib/rack/urlmap.rb:41:in
each' /usr/lib/ruby/gems/1.8/gems/rack-1.1.0/lib/rack/urlmap.rb:41:incall’
/usr/lib/ruby/gems/1.8/gems/rails-2.3.8/lib/rails/rack/log_tailer.rb:17:in
call' /usr/lib/ruby/gems/1.8/gems/rack-1.1.0/lib/rack/content_length.rb:13:incall’
/usr/lib/ruby/gems/1.8/gems/rack-1.1.0/lib/rack/handler/webrick.rb:48:in
service' /usr/lib/ruby/1.8/webrick/httpserver.rb:104:inservice’
/usr/lib/ruby/1.8/webrick/httpserver.rb:65:in run' /usr/lib/ruby/1.8/webrick/server.rb:173:instart_thread’
/usr/lib/ruby/1.8/webrick/server.rb:162:in start' /usr/lib/ruby/1.8/webrick/server.rb:162:instart_thread’
/usr/lib/ruby/1.8/webrick/server.rb:95:in start' /usr/lib/ruby/1.8/webrick/server.rb:92:ineach’
/usr/lib/ruby/1.8/webrick/server.rb:92:in start' /usr/lib/ruby/1.8/webrick/server.rb:23:instart’
/usr/lib/ruby/1.8/webrick/server.rb:82:in start' /usr/lib/ruby/gems/1.8/gems/rack-1.1.0/lib/rack/handler/webrick.rb:14:inrun’
/usr/lib/ruby/gems/1.8/gems/rails-2.3.8/lib/commands/server.rb:111
/usr/local/lib/site_ruby/1.8/rubygems/custom_require.rb:31:in
gem_original_require' /usr/local/lib/site_ruby/1.8/rubygems/custom_require.rb:31:inrequire’
script/server:3