Herbert's Wormhole by Peter Nelson

Herbert Slewg and his hapless, video game–addicted neighbor Alex Filby have stumbled upon what Einstein could only theorize about: a wormhole through the space/time continuum. They travel 100 years into the future of their no-longer-boring town and are mistaken for alien slayers . . . in a world run by a benevolent alien race with cheerful Australian accents and uncomfortably fake facial hair. Herbert, Alex, and their mutual crush, Sammi Clementine, century-hop across time in order to outwit a disgruntled “G’Dalien. By foiling his evil plot, they save the planet and become 22nd-century hometown heroes in this smart-alecky (but friendly), inventive, wry, and very visual creation.