The Boy Next Door by Meg Cabot (2002)

Sometimes I love Meg Cabot, but she writes a lot of books and sometimes she's just phoning it in.  This novel, however, is adorable.  Columnist chick has romantic troubles and hilarity ensues. Told completely through emails sent by and to gossip columnist Mel Fuller, this laugh-out-loud funny novel is an absolutely delightful read.  The follow-up novel, Every Boy's Got One has more emails and notes from characters tangentially related to those in The Boy Next Door. Girl cartoonist travels to Italy for her friend's wedding. Romantic troubles and hilarity ensue.  Also cute.