Delete all products and reset product id’s in magento 1.7.0.2

 SET FOREIGN_KEY_CHECKS = 0; 
 
TRUNCATE TABLE `catalog_product_bundle_price_index`; 
TRUNCATE TABLE `catalog_product_bundle_selection`; 
TRUNCATE TABLE `catalog_product_bundle_selection_price`; 
TRUNCATE TABLE `catalog_product_bundle_option_value`; 
TRUNCATE TABLE `catalog_product_bundle_option`; 
TRUNCATE TABLE `catalog_product_entity_datetime`; 
TRUNCATE TABLE `catalog_product_entity_decimal`; 
TRUNCATE TABLE `catalog_product_entity_gallery`; 
truncate table `catalog_product_entity_group_price`; 
TRUNCATE TABLE `catalog_product_entity_int`; 
TRUNCATE TABLE `catalog_product_entity_media_gallery`; 
TRUNCATE TABLE `catalog_product_entity_media_gallery_value`; 
TRUNCATE TABLE `catalog_product_entity_text`; 
TRUNCATE TABLE `catalog_product_entity_tier_price`; 
TRUNCATE TABLE `catalog_product_entity_varchar`; 
TRUNCATE TABLE `catalog_product_flat_1`; 
TRUNCATE TABLE `catalog_product_link`; 
TRUNCATE TABLE `catalog_product_link_attribute_decimal`; 
TRUNCATE TABLE `catalog_product_link_attribute_int`; 
TRUNCATE TABLE `catalog_product_link_attribute_varchar`; 
TRUNCATE TABLE `catalog_product_option`; 
TRUNCATE TABLE `catalog_product_option_price`; 
TRUNCATE TABLE `catalog_product_option_title`; 
TRUNCATE TABLE `catalog_product_option_type_price`; 
TRUNCATE TABLE `catalog_product_option_type_title`; 
TRUNCATE TABLE `catalog_product_option_type_value`; 
TRUNCATE TABLE `catalog_product_super_attribute_label`; 
TRUNCATE TABLE `catalog_product_super_attribute_pricing`; 
TRUNCATE TABLE `catalog_product_super_attribute`; 
TRUNCATE TABLE `catalog_product_super_link`; 
TRUNCATE TABLE `catalog_product_enabled_index`; 
TRUNCATE TABLE `catalog_product_website`; 
TRUNCATE TABLE `catalog_category_product_index`; 
 
TRUNCATE TABLE `catalog_category_product`; 
 
TRUNCATE TABLE `catalog_product_entity`; 
truncate table `catalog_product_relation`; 

TRUNCATE TABLE `cataloginventory_stock_item`; 
TRUNCATE TABLE `cataloginventory_stock_status`; 
SET FOREIGN_KEY_CHECKS = 1; 

http://www.magentocommerce.com/boards/viewthread/20553/P45/#t443418