YEAR IN REVIEW: Blink-182 announce an "indefinite hiatus" (read: break-up), after rehearsals for a benefit gig devolve into arguments. Mark expands into producing, Travis records with Transplants and gets a reality series, the two of them form +44, and Tom spends much of the year in silence, until his big announcement of a new band, Angels & Airwaves, in the fall.
 
1/4/2005: blink-182 appear on Fuse's 100%!

1/10/2005: Mark is interviewed for Risen magazine.
1-2/2005 (undated):

• Blink-182 begin rehearsals for the "Music For Relief" Tsunami benefit show. In Mark's 2006 b182.com "tell-all," he writes, "At one of the rehearsals, we started talking arguing about our forced break, the greatest hits record, and the possibility of recording the next album. [...] The next day our manager called and informed us that, 'as of today, Tom DeLonge is no longer a member of blink-182.'"

• Mark tweets in 2011: "Foo Fighters movie: the scene where Chris Shifflet tries out for the band is the EXACT room blink-182 broke up in in 2005." He's referencing the Foo Fighters documentary Back and Forth, and, upon further inspection, the studio in question is Mates Rehearsal Studios in North Hollywood.

2/3/2005: Tom calls in to a TRL Tsunami Relief Special.

2/16/2005: Blink confirm their appearance in September at the Chimera Music Festival, which was cancelled just days later.
2/18/2005: Blink-182's official website is updated with this statement: "Due to unexpected circumstances, we are unable to play the "Music For Relief" Tsunami benefit show tonight [February 18th]."
2/21/2005: Dave Navarro posts the following on his blog, 6767.com: "The big shock came when Blink-182 pulled out. Evidently, they broke up yesterday. I am surprised they couldn't hang in there one more day in order to do Southeast Asia a service like this, but having said that, I know how it can get when it's just not working anymore."
2/22/2005: Blink-182 announce their indefinite hiatus: "For over a decade, Blink-182 has toured, recorded and promoted nonstop all while trying to balance relationships with family and friends. To that end, the band has decided to go on an indefinite hiatus to spend some time enjoying the fruits of their labors with loved ones."
2/23/2005: Mark graces the cover of Bass Guitar Magazine (UK Edition).
4/6/2005: 

• Meet the Barkers premieres on MTV.

• Mark gives an interview to Rhapsody.

4/7/2005: Mark makes an appearance on Fuse's Daily Download.

4/8/2005: The first news breaks of +44’s formation via MTV News: "Blink-182's Hoppus, Barker Form Electronic Side Project”.
4/11/2005: Mark guest hosts an episode of Stevens Untitled Rock Show.
4/12/2005: Mark guest hosts an episode of Stevens Untitled Rock Show.
6/6/2005: Rumors abound online that Blink will reunite for KROQ's Inland Invasion concert on 9/17.

6/21/2005: Transplants’ second album, Haunted Cities, is released.

8/29/2005: Transplants were scheduled to perform at Koko in London. The show was cancelled along with the rest of the tour. Ticket

08/30/2005: Transplants were scheduled to perform at the Astoria in London. The show was cancelled along with the rest of the tour. Ticket  

9/13/2005: 

• Mark’s new podcast, Hi My Name is Mark, premieres.

• Though the podcast would only run until 2007, Mark would resurrect the HMNIM name for his website and clothing brand over the next decade.

9/15/2005: Tom announces Angeles & Airwaves, promising the “greatest rock-n-roll revolution for this generation”

9/19/2005: Geffen announces Blink’s Greatest Hits compilation, due out 11/1.

10/28/2005: Tom gives a large interview to MTV, mainly centering on the band's implosion.
10/31/2005: Blink's first compilation album, Greatest Hits, is released.
11/9/2005: Greatest Hits debuts at number six in the US, selling 72,000 copies in its opening week.

11/24/2005: Tom gives his first live interview about Angels & Airwaves via Macbeth Footwear’s website.

12/6/2005: Angels & Airwaves are featured in Alternative Press.

12/13/2005: “No It Isn’t” — +44’s first official release — debuts for digital download on their official website. Perhaps uncoincidentally, it’s released on Tom’s birthday.

12/19/2005: In the Rolling Stone Podcast, Tom and his new AVA bandmates — David Kennedy, Ryan Sinn, and Atom Willard — discuss the band’s formation and music.