MP3 players. Digital music sales rose, accounting for 6% of all music sales in 2005. Digital music options were integrated into other devices such as smartphones and the popular PlayStation Portable (PSP). By the latter half of the decade, generic MP3 players were starting to mimic the features of the extremely popular iPod and Zune. As a result of the widespread popularity and social impact of Google Search, the word "google" came to be used as a verb. Adobe Flash technology reached the point of being able to make video players. As a result, YouTube, a website which allows uploading and viewing videos, was created. YouTube's popularity grew explosively and it was acquired by Google. Data storage prices continued to drop, going from approximately $7 USD per GB in early 2000 to $0.07 USD per GB in 2009. Due to an increase in capacity, USB flash drives rapidly replaced Zip disks and floppy discs (by Iomega) and 3.5-inch diskettes. The first 2 TB hard drives were developed and beginning to be used. Windows XP and Microsoft Office 2003 became the ubiquitous industry standard in personal computer software, although their successors Windows Vista and, by the end of the decade, Windows 7, saw increasing market penetration. Open-source and free software continued to be a notable but minority interest, with versions of the Linux kernel gaining in popularity, as well as the Mozilla Firefox web browser and the OpenOffice.org productivity suite. Blogs, portals, intranets and wikis became common electronic dissemination methods for professionals, amateurs, and businesses to conduct knowledge management. Wikipedia began and grew, becoming both the largest encyclopedia, and the most widely read wiki in the world. Wireless networks became ever more commonplace in homes, education institutes and urban public spaces. Peer-to-peer technology was used in a major way, such as internet telephony (Skype), file-sharing. The Internet became a major source of all types of media, from music to movies, thanks initially to file-sharing peer-to-peer programs such as Kazaa and LimeWire. The debate continued over the ethics of file sharing. Legal music download services such as iTunes and streaming services such as Spotify opened up new markets. The video game industry's profits surpassed the movie industry's in 2004. The US tech bubble burst for the most part in early 2000s and after three years of negative growth the technology market began its rebound in 2003. Social networking websites like Myspace and